Introduction to IT

Node
In a network, a node is a connection point, either a redistribution point or an end point for data transmissions. In general, a node has programmed or engineered capability to recognize and process or forward transmissions to other nodes.

Client
A client is the requesting program or user in a client/server relationship. For example, the user of a Web browser is effectively making client requests for pages from servers all over the Web. The browser itself is a client in its relationship with the computer that is getting and returning the requested HTML file. The computer handling the request and sending back the HTML file is a server.

Server
In information technology, a server is a computer program that provides services to other computer programs and their users in the same or other computers. The computer that a server program runs in is also frequently referred to as a server. In the server programming model, a server is a program that awaits and fulfills requests from client programs in the same or other computers. A given application in a computer may function as a client with requests for services from other programs and also as a server of requests from other programs.

Hub
A hub is the central part of a wheel where the spokes come together.In describing network topologies, a hub topology consists of a main circuit to which a number of outgoing lines can be attached, each providing one or more connection port for device to attach to. For Internet users not connected to a local area network, this is the general topology used by your access provider. Other common network topologies are the bus network and the ring network. As a network product, a hub may include a group of modem cards for dial-in users, a gateway card for connections to a local area network. For example, Ethernet, and a connection to a line.

Network Interface Card (NIC)
A network interface card (NIC) is a computer circuit board or card that is installed in a computer so that it can be connected to a network. Personal computers and workstations on a local area network (LAN) typically contain a network interface card specifically designed for the LAN transmission technology, such as Ethernet or Token Ring. Network interface cards provide a dedicated, full-time connection to a network. Most home and portable computers connect to the Internet through as-needed dial-up connection. The modem provides the connection interface to the Internet service provider.

Network Operating System (NOS)
A network operating system (NOS) is a computer operating system system that is designed primarily to support workstation, personal computer, and, in some instances, older terminal that are connected on a local area network (LAN). Artisoft's LANtastic, Banyan VINES, Novell's NetWare, and Microsoft's LAN Manager are examples of network operating systems. In addition, some multi-purpose operating systems, such as Windows NT and Digital's OpenVMS come with capabilities that enable them to be described as a network operating system.

Distributed Processing
Refers to any of a variety of computer systems that use more than one computer, or processor, to run an application. This includes parallel processing, in which a single computer uses more than one CPU to execute programs. More often, however, distributed processing refers to local-area networks (LANs) designed so that a single program can run simultaneously at various sites. Most distributed processing systems contain sophisticated software that detects idle CPUs on the network and parcels out programs to utilize them.

Host Computer
Main or controlling computer connected to other computers or terminals to which it provides data or computing services via a network. It is similar to a server in a client-server architecture. In the modern peer to peer networking every computer is a peer and also a host to every other computer connected to the network. The name reflects the biological relationship between a host and parasites.

Network Manager
NetworkManager is a software utility aimed at simplifying the use of computer networks on Linux and other Unix-like operating systems. NetworkManager is designed in two components: a service which manages connections and reports network changes, and a graphical desktop applet which allows the user to manipulate network connections.

Magnetic Ink Character Recognition (MICR)
Magnetic Ink Character Recognition is a character recognition system that uses special ink and characters. When a document that contains this ink needs to be read, it passes through a machine, which magnetizes the ink and then translates the magnetic information into characters. MICR technology is used by banks. Numbers and characters found on the bottom of checks (usually containing the check number, sort number, and account number) are printed using Magnetic Ink. To print Magnetic Ink need, you need a laser printer that accepts MICR toner.
MICR provides a secure, high-speed method of scanning and processing information


Optical Character Recognition
OCR, optical character recognition refers to the branch of computer science that involves reading text from paper and translating the images into a form that the computer can manipulate (for example, into ASCII codes). An OCR system enables you to take a book or a magazine article, feed it directly into an electronic computer file, and then edit the file using a word processor.



Optical-mark Recognition (OMR)
The technology of electronically extracting intended data from marked fields, such as checkboxes and fill-infields, on printed forms. OMR technology scans a printed form and reads predefined positions and records where marks are made on the form. This technology is useful for applications in which large numbers of hand-filled forms need to be processed quickly and with great accuracy, such as surveys, reply cards, questionnaires and ballots. A common OMR application is the use of “bubble sheets” for multiple-choice tests used by schools. The student indicates the answer on the test by filling in the corresponding bubble, and the form is fed through an optical mark reader (also abbreviated as OMR, a device that scans the document and reads the data from the marked fields. The error rate for OMR technology is less than 1%.


Dot Matrix Printer
A type of printer that produces characters and illustrations by striking pins against an ink ribbon to print closely spaced dots in the appropriate shape. Dot-matrix printers are relatively expensive and do not produce high-quality output. However, they can print to multi-page forms (that is, carbon copies), something laser and ink-jet printers cannot do.





Plotters
A device that draws pictures on paper based on commands from a computer. Plotters differ from printers in that they draw lines using a pen. As a result, they can produce continuous lines, whereas printers can only simulate lines by printing a closely spaced series of dots. Multicolor plotters use different-colored pens to draw different colors.In general, plotters are considerably more expensive than printers. They are used in engineering applications where precision is mandatory.





Photo Printer
A printer specialized for smaller prints such as 4x6" and 5x7". When first introduced in the mid-1990s, photo printers used dye sublimation for high quality printing because inkjet printing was not quite up to par. Since then, inkjet technology has greatly improved, and most photo printers are inkjets. Epson, Canon and HP are major players in this market. See digital camera, photo scanner, inkjet printer and dye sublimation printer.





Portable Printer
Portable printer gives you the freedom to print from nearly anywhere. You can print high-quality documents and photos from your laptop PC, or any number of portable devices, such as PDAs, digital cameras, camera phones, and memory cards.




Fax Machine
A "fax machine" usually consists of an image scanner, a modem, and a printer.Although devices for transmitting printed documents electrically have existed, in various forms, since the 19th century, modern fax machines became feasible only in the mid-1970s as the sophistication increased and cost of the three underlying technologies dropped. Digital fax machines first became popular in Japan, where they had a clear advantage over competing technologies like the teleprinter.

Multifunctional Devices
Multifunctional devices have evolved from photocopiers and have many areas of functionality, predominantly printing, faxing, scanning and integration with other applications.









Internet Telephones
A category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls. For users who have free, or fixed-price Internet access, Internet telephony software essentially provides free telephone calls anywhere in the world. To date, however, Internet telephony does not offer the same quality of telephone service as direct telephone connections.



Telephony
It encompasses the general use of equipment to provide voice communication over distances, specifically by connecting telephones to each other.
Telephones were originally connected directly together in pairs. Each user had separate telephones wired to the various places he might wish to reach. This became inconvenient when people wanted to talk to many other telephones, so the telephone exchange was invented. Each telephone could then be connected to other local ones, thus inventing the local loop and the telephone call. Soon, nearby exchanges were connected by trunk lines, and eventually distant ones were as well.