The web of issues can profit a variety of organizations. However IoT methods require professionals who know their method across the know-how and perceive what it takes to plan, deploy and preserve an IoT system.
When interviewing people for these positions, IT leaders and different decision-makers should assess a candidate’s talent ranges and talent to understand elementary IoT ideas. They have to ask the correct IoT interview questions of potential workers and know what to search for within the solutions.
Listed below are the 30 prime interview questions and solutions to assist with this evaluation. These questions may help organizations in want of IoT expertise decide whether or not a person has the data needed to satisfy the calls for of the web of issues.
High IoT interview questions and solutions
1. What’s IoT?
IoT refers back to the web of issues. It’s a system of interrelated bodily gadgets which might be every assigned a singular identifier. IoT extends web connectivity past conventional platforms, similar to PCs, laptops and cell phones.
IoT gadgets can switch information over a community with out requiring human interplay. The gadgets include embedded methods that may carry out various kinds of operations, similar to gathering details about the encircling setting, transmitting information over a community, responding to distant instructions or finishing up actions based mostly on the collected information. IoT gadgets can embody wearables, implants, automobiles, equipment, smartphones, home equipment, computing methods or every other system that may be uniquely recognized, switch information and take part in a community.
2. What industries can profit from IoT?
A variety of industries can profit from IoT, together with healthcare, agriculture, manufacturing, automotive, public transportation, utilities and power, environmental, good cities, good properties and client gadgets.
3. How can IoT profit the healthcare trade?
IoT advantages the healthcare trade — typically by means of what is known as the web of medical issues — in a number of methods, together with the next:
- Wearable gadgets that may monitor a affected person’s vitals or well being situation and robotically ship standing updates again to the medical facility.
- Implanted IoT gadgets that may assist preserve a affected person’s well being and robotically present medical amenities with information about implants and their operations. Some implants may also be adjusted with out requiring extra surgical procedure.
- Medical amenities can present sufferers with wearables that make it simpler to observe and observe them, particularly sufferers who get simply confused or are younger. Wearables may observe affected person move to optimize processes, similar to admitting or discharging.
- Medical amenities can present wearables to workers to assist enhance productiveness by monitoring their actions after which analyzing the collected information to find out higher methods to handle workflow and optimize every day duties.
- Medical amenities and sufferers can higher handle medicines all through all phases of the medicine cycle — from writing and filling a prescription to monitoring utilization and reminding sufferers when it is time to take particular doses.
- Medical amenities can enhance how they handle their bodily environments and belongings, in addition to inside operations, whereas making it simpler to automate sure processes, similar to monitoring and ordering provides. IoT can probably additionally facilitate robotics for finishing up routine duties.
- Medical amenities can use IoT to attach medical tools in several areas to allow them to extra successfully share information and coordinate affected person efforts, whereas eliminating additional paperwork and handbook processes.
- Medical tools can use IoT gadgets to observe procedures to make sure no errors happen that might jeopardize human well being.
4. What is supposed by a wise metropolis in IoT?
A good metropolis is an city space that makes use of IoT applied sciences to attach metropolis providers and improve their supply. Good cities may help cut back crime, optimize public transportation, enhance air high quality, streamline site visitors move, decrease power use, handle infrastructure, cut back well being dangers, simplify parking, handle utilities and enhance a wide range of different processes. Utilizing sensor-driven information assortment, the good metropolis can orchestrate and automate a variety of providers, whereas lowering prices and making these providers simpler to entry for extra individuals.
Implementing a wise metropolis takes extra than simply spreading IoT gadgets round. Town wants a complete infrastructure for deploying and sustaining these gadgets, in addition to for processing, analyzing and storing the info. The system requires subtle functions that incorporate superior applied sciences, similar to synthetic intelligence (AI) and predictive analytics. The system should additionally tackle safety and privateness issues, in addition to interoperability points that may come up. Not surprisingly, such an effort can take important money and time, but the advantages of a wise metropolis may very well be effectively well worth the effort for the municipality that may make it work.
5. What are the principle elements of the IoT structure?
The IoT structure consists of the next elements:
- Good gadgets. Embody embedded methods for finishing up duties similar to gathering and transmitting information or responding to instructions from exterior management and administration methods.
- Knowledge processing platforms. Embody the {hardware} and software program essential to course of and analyze the info coming in over the community from the IoT gadgets.
- Storage platforms. Handle and retailer the info and interface with the info processing platform to assist its operations.
- Community infrastructure. Facilitates communications between the gadgets and the info processing and storage platforms.
- UI. Allows people to attach on to IoT gadgets to configure and handle them, in addition to confirm their standing and troubleshoot them. The UI may additionally present a technique to view the system’s collected information or generated logs. This interface is separate from these used to view information collected on the info processing or storage platforms.
There are different methods to categorize IoT structure. For instance, deal with information processing and storage platforms as a single part, or the break the info processing platform into a number of elements, similar to {hardware} and software program.
6. What’s an embedded system on an IoT system?
An embedded system is a mix of {hardware}, software program and firmware that is configured for a selected function. It is basically a small laptop that may be embedded in mechanical or electrical methods, similar to vehicles, industrial tools, medical gadgets, good audio system or digital watches. An embedded system is likely to be programmable or have fastened performance.
It is usually made up of a processor, reminiscence, energy provide and communication ports and consists of the software program needed to hold out operations. Some embedded methods may additionally run a light-weight OS, similar to a stripped-down model of Linux.
An embedded system makes use of communication ports to transmit information from its processor to a peripheral system, which is likely to be a gateway, central information processing platform or one other embedded system. The processor is likely to be a microprocessor or a microcontroller, which is a microprocessor that features built-in reminiscence and peripheral interfaces. To interpret the collected information, the processor makes use of specialised software program saved in reminiscence.
Embedded methods can fluctuate considerably between IoT gadgets by way of complexity and performance, however all of them present the capability to course of and transmit information.
7. What are the first {hardware} elements that make up an embedded system?
An embedded system can embody any of the next varieties of {hardware} elements:
- Sensor or different enter system. Gathers data from the observable world and converts it to {an electrical} sign. The kind of information gathered is dependent upon the enter system.
- Analog-to-digital converter. Adjustments {an electrical} sign from analog to digital.
- Processor. Processes the digital information the sensor or different enter system collects.
- Reminiscence. Shops specialised software program and the digital information the sensor or different enter system collects.
- Digital-to-analog converter. Adjustments the digital information from the processor into analog information.
- Actuator. Takes motion based mostly on the info collected from a sensor or different enter system.
An embedded system may comprise a number of sensors and actuators. For instance, a system may embody a number of sensors that collect environmental data, which is transformed and despatched to the processor. As soon as processed, the info is transformed once more and despatched on to a number of actuators, which perform prescribed actions.
8. What’s a sensor in an IoT system?
A sensor is a bodily object that detects and responds to enter from its surrounding setting, basically studying the setting for data. For instance, a sensor that measures temperatures inside a bit of heavy equipment detects and responds to the temperature inside that equipment, versus registering the skin temperature. The knowledge {that a} sensor gathers is usually transmitted electronically to different elements in an embedded system, the place it’s transformed and processed as needed.
The IoT trade helps many varieties of sensors, together with these that may measure mild, warmth, movement, moisture, temperature, stress, proximity, smoke, chemical compounds, air high quality or different environmental circumstances. Some IoT gadgets include a number of sensors to seize a mixture of information. For instance, an workplace constructing may embody good thermostats that observe each temperature and movement. That method, if nobody is within the room, the thermostat robotically lowers the warmth.
A sensor is completely different from an actuator, which responds to the info the sensor generates.
9. What are some examples of sensors that can be utilized in agriculture?
Many sensors can be found for agriculture, together with the next:
- Airflow. Measures soil’s air permeability.
- Acoustic. Measures the extent of noise from pests.
- Chemical. Measures ranges of a selected chemical, similar to ammonium, potassium or nitrate, or measures such circumstances as pH ranges or presence of a selected ion.
- Electromagnetic. Measures the soil’s skill to conduct electrical cost, which can be utilized to find out traits similar to water content material, natural matter or diploma of saturation.
- Electrochemical. Measures the vitamins throughout the soil.
- Humidity. Measures the moisture throughout the air, similar to in a greenhouse.
- Soil moisture. Measures the wetness of the soil.
10. What’s a thermocouple sensor?
A thermocouple sensor is a typical sort of sensor that measures temperature. The sensor consists of two dissimilar electrical metallic conductors joined at one finish to kind {an electrical} junction, which is the place the temperature is measured. The 2 metallic conductors produce a small voltage that may be interpreted to calculate the temperature. Thermocouples are available a number of sorts and sizes, are cheap to construct and are extremely versatile. They will additionally measure a variety of temperatures, making them effectively suited to a wide range of functions, together with scientific analysis, industrial settings, dwelling home equipment and different environments.
11. What are a number of the essential variations between Arduino and Raspberry Pi?
Arduino and Raspberry Pi are digital prototyping platforms used extensively in IoT gadgets. Desk 1 describes a number of the variations between the 2 platforms.
12. What are GPIO pins in Raspberry Pi platforms?
Common-purpose I/O (GPIO) is a normal interface that Raspberry Pi and different microcontrollers use to connect with exterior digital elements. Latest Raspberry Pi fashions are configured with 40 GPIO pins, that are used for a number of functions. For instance, GPIO pins provide 3.3 volt or 5 volt direct present energy, present a floor for gadgets, function a serial peripheral interface bus, act as a common asynchronous receiver/transmitter or ship different performance. One of many greatest benefits of Raspberry Pi GPIO pins is that IoT builders can management them by means of software program, making them particularly versatile and in a position to serve particular IoT functions.
13. What position does a gateway play in IoT?
An IoT gateway is a bodily system or software program program that facilitates communications between IoT gadgets and the community that carries system information to a centralized platform, similar to the general public cloud, the place information is processed and saved. Good system gateways and cloud endpoint safety merchandise can transfer information in each instructions, whereas serving to to guard information from being compromised, typically using such strategies as tamper detection, encryption, crypto engines or {hardware} random quantity mills. Gateways may additionally embody options that improve IoT communications, similar to caching, buffering, filtering, information cleaning and even information aggregation.
14. What’s the OSI mannequin and what communication layers does it outline?
The Open Techniques Interconnection (OSI) mannequin supplies a basis for web communication, together with IoT methods. The OSI mannequin defines a normal for a way gadgets switch information and talk with one another over a community and is split into seven layers that construct on prime of one another:
- Layer 1: Bodily layer. Transports information utilizing electrical, mechanical or procedural interfaces, sending bits from one system to a different alongside the community.
- Layer 2: Knowledge hyperlink layer. A protocol layer that handles how information is moved into and out of a bodily hyperlink in a community. It additionally addresses bit transmission errors.
- Layer 3: Community layer. Packages information with the community tackle data and selects the suitable community routes. It then forwards the packaged information up the stack to the transport layer.
- Layer 4: Transport layer. Transfers information throughout a community, whereas offering error-checking mechanisms and information move controls.
- Layer 5: Session layer. Establishes, authenticates, coordinates and terminates conversations between functions. It additionally reestablishes connections after interruptions.
- Layer 6: Presentation layer. Interprets and codecs the info for the software layer utilizing semantics accepted by the appliance. It additionally carries out required encryption and decryption operations.
- Layer 7: Utility layer. Allows an finish consumer, whether or not software program or human, to work together with the info by means of the mandatory interfaces.
15. What are a number of the protocols used for IoT communication?
The next checklist consists of lots of the protocols getting used for IoT:
Mobile IoT protocols, similar to LTE-M, narrowband IoT and 5G may facilitate IoT communications. The truth is, 5G guarantees to play a major position within the coming onslaught of IoT gadgets.
16. What are the principle variations between Bluetooth and Bluetooth LE?
Bluetooth, typically known as Bluetooth Basic, is usually used for various functions than Bluetooth Low Power. Bluetooth Basic can deal with way more information however consumes much more energy. Bluetooth LE requires much less energy however cannot trade practically as a lot information. Desk 2 supplies an summary of a number of the particular variations between the 2 applied sciences.
17. What influence may IPv6 have on IoT?
Web Protocol Model 6, generally known as IPv6, is an improve from IPv4. One of the important modifications is IPv6 will increase the scale of IP addresses from 32 bits to 128 bits. Due to its 32-bit limitation, IPv4 can assist solely about 4.2 billion addresses, which has already proved inadequate. The mounting variety of IoT gadgets and different platforms that use IP addresses requires a system that may deal with future addressing wants. The trade designed IPv6 to accommodate trillions of gadgets, making it effectively suited to IoT. IPv6 additionally guarantees enhancements in safety and connectivity. It is the extra IP addresses that take middle stage, nonetheless, which is why many consider that IPv6 will play a pivotal position sooner or later success of IoT.
18. What’s the Zigbee Alliance?
The Zigbee Alliance is a gaggle of organizations working collectively to create, evolve and promote open requirements for IoT platforms and gadgets. It is creating international requirements for wi-fi device-to-device IoT communication and certifies merchandise to assist guarantee interoperability. Certainly one of its most well-known efforts is Zigbee, an open customary for implementing low-power, self-organizing mesh networks. Zigbee-certified merchandise can use the identical IoT language to attach and talk with one another, lowering interoperability points. Zigbee relies on the IEEE 802.15 specification however provides community and safety layers along with an software framework.
19. What are some use circumstances for IoT information analytics?
The next use circumstances signify methods IoT information analytics can profit organizations:
- Forecasting buyer necessities and needs to raised plan product options and launch cycles, in addition to ship new value-added providers.
- Optimizing HVAC tools in workplace buildings, procuring malls, medical facilities, information facilities and different enclosed environments.
- Enhancing the extent of care given to sufferers with related circumstances, whereas with the ability to higher perceive these circumstances and goal the wants of particular people.
- Optimizing supply operations, similar to scheduling, routing and automobile upkeep, in addition to lowering gas prices and emissions.
- Buying in-depth data of how shoppers use their merchandise so an organization can develop extra strategic advertising campaigns.
- Predicting and figuring out potential safety threats to raised shield information and meet compliance necessities.
- Monitoring how utilities are delivered to clients throughout areas and higher understanding their utilization patterns.
- Enhancing agricultural practices to attain extra considerable but sustainable yields.
- Optimizing manufacturing operations to make higher use of apparatus and enhance workflows.
20. How can edge computing profit IoT?
Edge computing can profit IoT in quite a few methods, together with the next:
- Supporting IoT gadgets in environments with restricted community connectivity, similar to cruise ships, agricultural settings, offshore oil rigs or different distant areas.
- Decreasing community congestion by preprocessing information in an edge setting after which transmitting solely the aggregated information to a central repository.
- Decreasing latency by processing the info nearer to the IoT gadgets producing that information, leading to faster response instances.
- Decreasing potential safety and compliance dangers by transmitting much less information throughout the web or by creating smaller community segments which might be simpler to handle and troubleshoot.
- Decentralizing huge cloud facilities to raised serve particular environments and cut back the prices and complexities that include transmitting, managing, storing and processing massive information units on a centralized platform.
21. How may 5G mobile networks influence IoT?
The approaching wave of 5G networks may influence IoT in a wide range of methods:
- Increased bandwidth and sooner throughputs make it potential to assist extra superior use circumstances, particularly those who require faster response instances, similar to site visitors management methods or automated public transportation.
- Organizations can distribute extra sensors to seize a wider vary of details about environmental components or tools habits, leading to extra complete analytics and a higher capability of automating operations each on the industrial stage and client stage.
- 5G may allow IoT on a extra complete scale in areas the place it is likely to be in any other case tough to attain, serving to industries similar to healthcare and agriculture.
- The sooner throughput and talent to deal with information from extra sensors makes it simpler to determine good cities, which require the next saturation of IoT gadgets.
- Producers may use 5G to raised observe stock all through its lifecycle, in addition to higher management workflows and optimize operations.
- 5G permits organizations and governments to reply extra shortly and effectively to various kinds of incidents, similar to medical emergencies, pipeline leaks, fires, site visitors accidents, climate occasions or pure disasters.
- Vehicles can profit from 5GÂ as automobiles develop into extra related, serving to to maintain them safer, higher maintained and extra gas environment friendly, whereas additionally making the autonomous automotive extra of a actuality.
22. What are a number of the greatest safety vulnerabilities that include IoT?
Safety stays an enormous a part of IoT. The Open Internet Utility Safety Venture has recognized the highest 10 IoT safety vulnerabilities, which embody the next:
- Weak, guessable or hardcoded passwords.
- Insecure community providers.
- Insecure ecosystem interfaces.
- Lack of safe replace mechanisms.
- Use of insecure or outdated elements.
- Inadequate privateness safety.
- Insecure information switch and storage.
- Lack of system administration.
- Insecure default settings.
- Lack of bodily hardening.
23. What steps can a corporation take to guard IoT methods and gadgets?
A company can take a number of steps to guard its IoT methods, together with the next:
- Incorporate safety on the design part, with safety enabled by default.
- Use public key infrastructures and X.509 certificates to safe IoT gadgets.
- Use software efficiency indicators to safeguard information integrity.
- Guarantee every system has a singular identifier, and implement endpoint hardening, similar to making gadgets tamper-proof or tamper-evident.
- Use superior cryptographic algorithms to encrypt information in transit and at relaxation.
- Defend networks by disabling port forwarding, closing unused ports, blocking unauthorized IP addresses and preserving community software program and firmware updated. Additionally, implement antimalware, firewalls, intrusion detection methods, intrusion prevention methods and any different needed protections.
- Use community entry management mechanisms to establish and stock IoT gadgets connecting to the community.
- Use separate networks for IoT gadgets that join on to the web.
- Use safety gateways to function intermediaries between the IoT gadgets and the community.
- Constantly replace and patch any software program that participates within the IoT system or is used to handle IoT elements.
- Present safety coaching and schooling for people who take part within the IoT system at any stage — whether or not planning, deploying, creating or managing.
24. What are the highest challenges of implementing an IoT system?
Organizations that wish to implement an efficient IoT system face a wide range of challenges, together with the next:
- IoT can generate huge volumes of information, and organizations should be capable of successfully handle, retailer, course of and analyze that information to understand the fullest potential from their IoT methods.
- In some circumstances, managing energy provides for IoT gadgets might be tough, particularly gadgets in hard-to-reach areas or those who depend on battery energy.
- Managing IoT gadgets might be an amazing endeavor even for essentially the most seasoned IT directors, who should typically take additional steps to observe and handle these gadgets.
- Sustaining community connectivity for a number of IoT system sorts generally is a important problem, particularly when these gadgets are extremely distributed or in distant areas, or if bandwidth is severely restricted.
- The lack of frequent IoT requirements could make it tough to deploy and handle massive numbers of IoT gadgets that come from completely different distributors and are based mostly on proprietary applied sciences that differ considerably from each other.
- Guaranteeing the reliability of an IoT system might be tough as a result of IoT gadgets are extremely distributed and should typically cope with different web site visitors. Pure disasters, disruptions in cloud providers, energy failures, system failures or different circumstances can have an effect on the elements that make up an IoT system.
- Complying with authorities laws represents one other important problem with IoT, particularly if working in a number of areas or in areas with conflicting or often altering laws.
- IoT methods face safety threats on many fronts —Â botnets, ransomware, area identify server threats, shadow IT, bodily vulnerabilities and different sources — and organizations should be capable of shield their IoT gadgets, community infrastructure, on-premises compute and storage sources, and all the info that comes with IoT.
25. What are the variations between IoT and IIoT?
Industrial web of issues (IIoT) is commonly outlined as a subset of IoT that focuses particularly on industrial settings, similar to manufacturing, agriculture or oil and gasoline. Nevertheless, some individuals within the trade outline IoT and IIoT as two separate efforts, with IoT targeted on the buyer facet of system connectivity. In both case, IIoT falls squarely on the economic facet of the equation and is anxious primarily with the usage of good sensors and actuators to boost and automate industrial operations.
Also called Trade 4.0, IIoT makes use of good machines that assist machine-to-machine (M2M) applied sciences or cognitive computing applied sciences, similar to AI, machine studying or deep studying. Some machines even incorporate each varieties of applied sciences. Good machines seize and analyze information in actual time and talk data that can be utilized to drive enterprise selections. When in comparison with IoT basically, IIoT tends to have stricter necessities in such areas as compatibility, safety, resilience and precision. Finally, IIoT goals to streamline operations, enhance workflows, enhance productiveness and maximize automation.
26. What are the principle variations between IoT and M2M?
The phrases IoT and M2M are typically used interchangeably, however they aren’t the identical. M2M permits networked gadgets to work together with one another and perform operations with out human interplay. For instance, M2M is commonly used to allow ATMs to speak with a central platform. M2M gadgets use point-to-point communication mechanisms to trade data utilizing a wired or wi-fi community. An M2M system usually depends on customary community applied sciences, similar to Ethernet or Wi-Fi, making it cost-effective for establishing M2M communication.
IoT is commonly thought-about an evolution of M2M that will increase connectivity capabilities to create a a lot bigger community of speaking gadgets, counting on IP-based applied sciences to facilitate that communication. Normal M2M methods have restricted scalability choices and are typically remoted methods which might be finest suited for easy device-to-device communication, usually with one machine at a time. IoT has a much wider vary that may combine a number of system architectures right into a single ecosystem, with assist for simultaneous communications throughout gadgets. Nevertheless, IoT and M2M are related in that each methods present a construction for exchanging information between gadgets with out human intervention.
27. What’s IoE?
The web of every little thing (IoE) is a conceptual leap that reaches past IoT — which focuses on issues — into an expanded realm of connectivity that includes individuals, course of and information, together with issues. The idea of IoE originated with Cisco, which said that the “benefit of IoE is derived from the compound impact of connecting people, process, data and things, and the value this increased connectedness creates as ‘everything’ comes online.”
By comparability, IoT refers solely to the networked connection of bodily objects, whereas IoE expands this community to incorporate people-to-people and people-to-machine connections. Cisco and different proponents consider that those that harness IoE will be capable of seize new worth by “connecting the unconnected.”
28. Which varieties of testing ought to be carried out on an IoT system?
Enterprises implementing an IoT system ought to conduct a wide range of testing, together with the next sorts:
- Usability. Ensures IoT system provides optimum UX, based mostly on the setting during which the system will usually be used.
- Performance. Ensures all options on the IoT system work as designed.
- Safety. Ensures that IoT gadgets, software program and infrastructure — community, compute and storage — meet all relevant safety necessities and regulatory requirements.
- Knowledge integrity. Ensures the integrity of the info throughout communication channels, all through processing operations and inside storage platforms.
- Efficiency. Ensures that IoT gadgets, software program and infrastructure present the efficiency essential to ship uninterrupted providers throughout the anticipated time-frame.
- Scalability. Ensures the IoT system can scale as needed to satisfy evolving necessities with out impacting efficiency or disrupting providers.
- Reliability. Ensures the IoT gadgets and methods can ship the anticipated stage of providers with out incurring pointless or extended downtimes.
- Connectivity. Ensures IoT gadgets and system elements can correctly talk with out disruptions in connectivity or information switch operations and may robotically get well from any disruptions with out incurring any information loss.
- Compatibility. Ensures compatibility points between IoT gadgets and different system elements are recognized and addressed and that gadgets might be added, moved or eliminated with out disruptions to providers.
- Exploratory. Ensures the IoT system works as anticipated beneath real-world circumstances, whereas detecting points that may not be caught by different varieties of testing.
29. What’s IoT asset monitoring?
IoT asset monitoring refers back to the strategy of utilizing IoT to observe the situation of a corporation’s bodily belongings, regardless of the place they’re positioned or how they’re getting used. Belongings can embody something from supply vans to medical tools to development instruments. Moderately than attempt to observe these belongings manually, an organization can use IoT asset monitoring to robotically establish the situation and motion of every tracked system, serving to save time and guarantee higher accuracy. On the similar time, organizations can use asset monitoring to simplify stock upkeep, enhance asset use, and optimize workflows and every day operations.
30. What’s Thingful?
Thingful is an IoT search engine that gives a geographical index of real-time information from related gadgets all over the world, utilizing information from thousands and thousands of present public IoT information sources. The gadgets that generate the info can span a wide range of use circumstances, similar to power, climate, aviation, delivery, air high quality or animal monitoring. The search engine permits customers to search out gadgets, information units and real-time information sources by means of geolocation and presents them utilizing a proprietary IoT system search rating methodology. With Thingful, customers can interoperate with thousands and thousands of related objects and sensors throughout the planet that generate real-time open information.
IoT managers can use Thingful to research traits, uncover patterns and establish anomalies, in addition to remedy issues utilizing present information. The search engine may assist them kick-start IoT innovation in a neighborhood and assist residents of that neighborhood be taught concerning the IoT information and setting round them. Thingful is effectively suited to neighborhood engagement initiatives constructed round information and information schooling. Customers can create accounts, arrange time-series experiments, and generate statistical and analytical visualizations. They will additionally combine native IoT information repositories.
Robert Sheldon is a technical guide and freelance know-how author. He has written quite a few books, articles and coaching supplies associated to Home windows, databases, enterprise intelligence and different areas of know-how.
