Wednesday, March 3, 2010

Computer Networks - Common Network Terms


In computer networks, a node is a connection point. It is a point in a network topology at which lines intersect or branch. A node is either a redistribution point or a communication endpoint. The definition of a node also a given protocol or agreed-upon language for transmitting data packets between the different machines. A physical network node is an active electronic device that is attached to a network, and is capable of sending, receiving, or forwarding information over a communications channel. In general, a node has programmed or engineered capability to recognize and process or forward transmissions to other nodes.


In Information Technology, a client is an application or system that accesses a remote service on server, by way of a network. Client is also refers as the user or requesting program 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 known as a server. Clients usually refer to the software that is the game in only multiplayer online games for the computer.


In computing, a server is a computer program that provides services to other computer programs (and their users) in the same or other computers. It is a combination of hardware or software designed to provide servers to clients. Also, a server is a computer program that provides services to other computer programs (and their users) in the same or other computers. Besides, the computer that a server program runs in is also frequently referred to as a server though it may be used for other purposes as well. When used alone, the term typically refers to a computer which may be running a server operating system but is also used to refer to any software or dedicated hardware capable of providing services.


In computer networks, hub is a common connection point for devices. Hubs are commonly used to connect segments of a LAN. A hub also contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets. There are a few types of hub. For example, a passive hub serves simply as a conduit for the data, enabling it to go from one device to another. An intelligent hub includes additional features that enables an administrator to monitor the traffic passing through the hub and to configure each port in the hub. Intelligent hubs are also referred as manageable hubs. Another type of hub is called a switching hub. It reads destination address of each packet and then forwards the packet to the correct port.

Network Interface Cards (NIC)

In Information Technology, a network interface card is usually referred to as a NIC. NIC is a device that installed in a computer so that it can be connected to a network. It allows computers to be joined together in a local area network, which is LAN. Networked computers communicate with each other using nodes. The network interface card acts as the liaison for the machine to both send and receive data on the LAN. It provides a dedicated, full-time connection to a network. For instance, personal computers and workstations on a local area network usually contain a network interface card specifically designed for the LAN transmission technology, such as Ethernet or Token Ring. A network operating system is the software that allows multiple computers to communicate, share files and hardware devices with one another. It contains components and programs that allow a computer on a network to serve requests from other computers for data and provide access to other resources such as printer and file systems. Network Operating System also helps people to build and run their own programs. Some examples of network operating systems that are used on personal computers include MAC OS X, Novell Netware, Microsoft Windows NT, Microsoft Windows 2000, Microsoft Windows XP, Sun Solaris, Linux, and etc.

Host Computer

A host computer in computing is the main or controlling computer which is connected to other computers or terminals to which it provides data or computing services via a network. It is a computer that is use to develop software for execution on another computer and to emulate another computer, also known as the target computer. In the modern peer to peer networking over the internet, every computer is a peer and also a host to every other computer connected to the network. It provides services other than simply acting as a store-and-forward processor or communication switch. A host computer at one level of a hierarchy may also function as a packet or message switch at another.

Network Manager

In computer networks, network manager is a set of co-operative tools that make networking simple and straightforward. Network Manager allows you to quickly move from one network to another regardless whether you are using wireless or wired. Network manager also acts as a service that manages connections and reports network changes and a graphical desktop applet which allows the user to manipulate network connections. It always ensures the network is protected from unauthorized users and is always responding to hardware and software malfunctions. Examples of network management products are IBM's NetView, HP's OpenView, Sun's SunNet Manager and Novell's NMS.

Monday, February 8, 2010

System Unit

SocketsA CPU socket or CPU slot is an electric component that attaches to a printed circuit board (PCB) and is designed to house a microprocessor. It is a special type of intergrated circuit socket designed for very high pin counts. A CPU socket provides many functions, including providing a physical structure to support the CPU, providing support for a heatsink, facilitating replacement (as well as reducing cost) and most importantly forming an electrical interface both with the CPU and the PCB. CPU sockets can most often be found in most desktop and server computers, particularly those based on the Intel x86 architecture on the motherboard.


A small piece of semiconducting materialon which an intergrated circuit is embedded. A typical chip is less than ¼-square inches and can contain millions of electronic components such as transistors. Computers consist of many chips placed on electronic boards ccalled printed circuit boards.


An opening in a computer where a circuit board can be inserted to add new capabilities to the computer. Nearly all personal computers except portables contain expansion slots for adding more memory, graphic capabilities, and support for special devices. The boards inserted into the expansion slots are called expansion boards, expansion cards , cards, add-in, and add-ons.
Expansion slots for PCs come in two basic sizes: half- and full-size. Half-size slots are also called 8-bit slots because they can transfer 8 bits at a time. Full-size slots are sometimes called 16-bit slots. In addition, modern PCs include PCI slots for expansion boards that connect directly to the PCI bus.

Bus lines

Graphics Card

An expansion card that interprets drawing instructions sent by the CPU, processes them via a dedicated graphics processor and writes the resulting frame data to the frame buffer. Also called video adapter (the term "graphics accelerator" is no longer in use).

Sound Card

A sound card (also referred to as an audio card) is a peripheral device that attaches to the ISA or PCI on a motherboard to enable the computer to input, process, and deliver sound.
The sound card's four main functions are: as a synthesizer (generating sounds), as a MIDI interface, analog-to-digital conversion (used, for example, in recording sound from a microphone), and digital-to-analog conversion (used, for example, to reproduce sound for a speaker). The three methods of sound synthesis are through frequency modulation technology, wave table, and physical modeling.

Modem Card

The modem card that is placed in the PCI slot of your computer operates at a faster speed. It is usually recommended for the average user but can cost more than other modem cards. The modem card that connects to the motherboard of your PC is more inexpensive than a PCI card but is not as reliable. A wireless modem card can fit into a computer's motherboard or it can be an external USB card. A wireless modem can also fit into a PCMCIA slot of a laptop. Wireless modem cards allow internet access by communicating with a router that is connected to a user's PC.

Network Interface Card

A computer network interface card (NIC) is the hardware added to the machine that allows it to communicate with the network. The hardware is now normally included with computers, especially in laptops that require wireless technology for network access. A network card is bound to an IP address, which is the address of the computer on the network. When deciding to create a large or small network, the NIC is a necessary component to consider.

Plug and Play

Plug and Play is a catchy phrase used to describe devices that work with a computer system as soon as they are connected. The user does not have to manually install drivers for the device or even tell the computer that a new device has been added. Instead the computer automatically recognizes the device, loads new drivers for the hardware if needed, and begins to work with the newly connected device.For example, if you connect a Plug-and-Play mouse to the USB port on your computer, it will begin to work within a few seconds of being plugged in. A non plug-and-play device would require you to go through several steps of installing drivers and setting up the device before it would work.While Plug and Play usually refers to computer peripheral devices, such as keyboards and mice, it can also be used to describe internal hardware. For example, a video card or hard drive may be a Plug and Play device, meaning the computer will recognize it as soon as it is installed. The only difference is that internal components usually require the computer to be turned off when they are installed, while external devices can typically be installed while the computer is running.

Serial Port

In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time. Throughout most of the history of personal computers, data transfer through serial ports connected the computer to devices such as terminals and various peripherals.

Parallel Port

A hardware interface that transfers one or more bytes simultaneously. A socket on a computer used to connect a printer or other device via a parallel interface (eight data bits transferring simultaneously). In the past, the parallel port was widely used for printers and occasionally for connecting other devices externally, but was superseded by USB.

Universal Serial Bus Port

(Universal Serial Bus is a widely used hardware interface for attaching a maximum of 127 peripheral devices to a computer. There are usually at least two USB ports on laptops and four USB ports on desktop computers. After appearing on PCs in 1997, USB quickly became popular for connecting keyboards, mice, printers and external drives and eventually replaced the PC's serial and parallel ports.USB devices are "hot swappable;" they can be plugged in and unplugged while the computer is on. This feature, combined with easy-to-reach ports on the front of the computer case, gave rise to the ubiquitous USB drive for backup and data transport.

Firewire Port

This high-speed interface has become a hot new standard for connecting peripherals (no pun intended). Created by Apple Computer in the mid-1990's, Firewire can be used to connect devices such as digital video cameras, hard drives, audio interfaces, and MP3 players, such as the Apple iPod, to your computer. A standard Firewire connection can transfer data at 400 Mbps, which is roughly 30 times faster than USB 1.1. This blazing speed allows for quick transfers of large video files, which is great for video-editing professionals. If 400 Mbps is still not fast enough, Apple Computer released new PowerMacs with Firewire 800 ports in early 2003. These ports support data transfer rates of 800 Mbps -- twice the speed of the original Firewire standard.

Monday, January 25, 2010

The Internet, The web and E-commerce


Business-to-consumer describes a transaction, product or service, or business strategy as targeted to the consumer market rather than the business market. In contrast, if the target is the consumer, the term business-to-consumer, or B2C, applies. A business-to-consumer sale means a sale to a consumer, even of a product normally sold to businesses. For instance, Dell might sell a high-end workstation to a computer game buff in a business-to-consumer sale. Similarly, a business-to-consumer product is one targeted toward consumers rather than businesses. Video games are an example. A business-to-consumer organization, like Proctor and Gamble, gets revenues primarily from consumers, not businesses. Not all businesses and services are exclusively business-to-consumer or business to business. Transaction that occurs between a company and a consumer , as opposed to a transaction between companies. (Business to Business) The term may also describe a company that provide goods or services
for consumers.


Consumer-to-Consumer in e-commerce involves the electronically-facilitated transactions between consumers through some third party. A common example is the online-auction, in which a consumer posts an item for sale and other consumers bid to purchase it; the third party generally charges a flat free or commision. The sites are only intermediaries, just there to match consumers. They do not have to check quality of the products being offered.
There are many sites offering free classifieds, auctions, and forums where individuals can buy and sell thanks to online payment systems like PayPal where people can send and receive money online with ease. eBay's auction service is a great example of where person-to-person transactions take place everyday since 1995.


E-Commerce or electronic commerce, is a subset of e-business, which is the purchasing, selling, and exchanging of goods and services over computer network through which transactions or terms of sale are performed electronically. In short, E-commerce is the buying and selling of goods and services on the Internet. In practice, this term and e-business are often used interchangeably. For online retail selling, the term of e-tailing is sometimes used. E-commerce can also be broken down into four main categories which are Business to Business, Business to Consumer, Consumer to Business, and Consumer to Consumer.

Internet Security Suite

Internet Security Suite means a suite of utilities for maintaining the security of a Windows PC. It is used to protect Websites and other electronic files from attack by hackers and viruses via internet. A poor Internet security policy can result in a substantial loss of productivity and a drop in consumer confidence. It includes more than a dozen utilities such as anti-virus, personal firewall, spam blocker and pop-up blocker.


JavaScript is programming or script language from Netscape. JavaScript code can be imbedded in HTML pages and interpreted by the Web browser (or client). JavaScript can also be run at the server as in Microsoft's Active Server Pages before the page is sent to the requestor. It is somewhat similar in capability to Microsoft's Visual Basics, Sun's TCL, the UNIX-derive Perl, and IBM's Rexx. In general, script languages are easier and faster to code in than the more structured and compiled languages such as C and C++. Script languages generally take longer to process than compiled languages, but are very useful for shorter programs. JavaScript is also used in Web site development to do things like automatically change a formatted date on a Web page, cause a linked-to page to appear in a pop-up window, or cause a text or a graphic image to change during a mouse rollover.


In computing, a plug-in consists of a computer program that interacts with a host application to provide a certain, usually very specific, function "on demand". Add-on is often considered the general term comprising plug-ins, extensions, and themes as subcategories. Most graphics and audio programs today support plug-ins since they are a convenient way to expand the capabilities of the program. Though some plug-ins may be shipped with the program, most are developed by third-parties and are sold separately. Plug-in is a hardware or software module that adds a specific feature or service to an existing application in order to enhance it's capability. A software plug-in is an add-on for a program that adds functionality to it. For example, a Photoshop plug-in (such as Eye Candy) may add extra filters that you can use to manipulate images. A browser plug-in (such as Macromedia Flash or Apple QuickTime) allows you to play certain multimedia files within your Web browser. VST plug-ins add effects for audio recording and sequencing programs such as Cubase and Logic Audio.


Spam is an unsolicited commercial advertisements distributed online. Most spam comes to people via email, but some spam also can be found in online chat rooms and message boards. Some people also label spam as any form of Internet advertising such as pop up browser windows. Besides, spam consumes a tremendous amount of network bandwidth on the Internet. Spam's continued existence depends on maintaining an audience of people who respond to the messages. In contrast to true spam, these forms of advertising are provided to people in the act of visiting websites are merely a "cost of doing business" to help support those sites' products and services.

Monday, January 18, 2010

Careers in IT


A webmaster is the person in charge of maintaining a Web site. The jobs of a webmaster include writing HTML for Web pages, designing the websites, organizing the website's structure, generating and revising web pages, responding to e-mails and comments about the Web site, examining traffic through the website and keeping the site up-to-date.

Computer Support Specialist

A computer support specialist is a person who helps people with computer problems. Some computer support specialists called help-desk technicians field phone calls or e- mails or make house calls for people who are having difficulty with a particular piece of computer hardware or software. Support specialists must also deal with both inexperienced users and computer- savvy programmers or software designers. They must be able to reduce technical information to simple language.

Technical Writer

A technical writers is a person who explains in simple language scientific and technical ideas that are difficult for the average reader to understand. Some write articles and reports on current trends in fields such as science and engineering. Technical writers may be employed to write policies and procedures for any type of operation—from banking to shipping. They may also write different kinds of instruction manuals—from how to use a new appliance to how to build a model airplane. Some write press releases and other promotional materials for companies that sell products or services.

Software Engineer

A software engineer is a licensed professional engineer who is schooled and skilled in the application of engineering discipline to the creation of software. A software engineer also creates the designs the programmer implements. Besides, a software engineer is also held accountable to a specific code of ethics.


A programmer is a person who writes, tests, and maintains source code that computers must follow in order to perform their functions. Programmers generally work under specifications provided by software engineers or systems analysts. Also, programmers usually have an entensive background in some form of computer coding language, which may include XML, PHP, Perl, HTML, or SQL.

Network Admistrator

A network admistrator is a person who manages a local area communications network (LAN) or wide area network (WAN) for an organization. Responsibilities include network security, installing new hardware and applications, monitoring software upgrades and daily activity, enforcing licensing agreements, developing a storage management program and providing for routine backups, not to mention ensuring that it is up and running all the time.

Database Administrator

A database administrator is a person who is responsible for the design and management of one or more database and for the evaluation, selection and implementation of database management systems. The database administrator would implement the database software that meets the requirements outlined by the organization's data administrator and system analysts. Their jobs might include controlling an organization's data resources, using data dictionary software to ensure data integrity and security, recovering corrupted data and eliminating data redundancy and uses tuning tools to improve database performance.

System Analyst

A system analyst is a person who is responsible for the development of an information system. Systems analysts design and modify systems by turning user requirements into a set of functional specifications, which are the blueprint of the system. They design the database or help design it if data administrators are available. They develop the manual and machine procedures and the detailed processing specifications for each data entry, update, query and report program in the system. System analysts should also identify the available system alternatives. These includes acquisition of a new system, modification of the old system and use of a third party's services.