Connecting to the Internet

MODEM

Modem stands for MODulator/DEModulator. Telephone lines were designed to transmit the human voice, not electronic data from computers, modems were invented to convert digital computersignals into a from that allows them to travel over phone lines.

Two Kinds of Modem

• Internal Modem
• External Modem

INTERNAL MODEM

Internal Modem

 is modem that plugged directly into the CPU. Physically internal modem in the form of a card that is plugged into one of the expansion slots on the mainboard, usually on the ISA or PCI slot. The use of this type of modem has several advantages, among others, are more efficient in terms of price point and more economical than an external modem. Since it has been installed on the CPU, then this type of modem does not require an adapter as well as an external modem to the system seem more concise without a lot of wires milling which could give the impression of less neat. Nevertheless, internal modem has a drawback as the absence of indicators that can be found on the external modem. Consequently rather difficult to monitor the status of the modem (though it can be done through software). In addition, internal modem does not use its own voltage source to be fed from the power supply to the CPU. The heat from the components in the circuit will also add an internal modem in the box CPU temperature.

External Modem

 is modem that installed outside of the CPU. External modem connected to the CPU via the COM port or USB. This type of modem typically uses separate voltage source in the form of an adapter. The advantage of using this type of modem is a pretty good portability so that to be easily removable for use on another computer. Besides, by using an external modem, there should be no expansion slots are sacrificed so that it can be used for other purposes, particularly if used mainboard provides few expansion slots. External modems are also equipped with an indicator light that allows us to monitor the status of the modem. Disadvantage, more expensive than the internal modem. External modems also require a separate place to put it though small.

BROADBAND

While all Broadband services make dial-up seem glacial by comparison, not all deliver the same speed. Most Broadband services are asymmetric, a fancy term that means, that the download speed is faster than the upload speed.

CABLE

Another option is high-speed Internet Access via cable TV. with speeds ranging from 512 kbps to 20 mbps, cable modems download data in seconds that make fifty times longer with a dial-up connections.

DSL

DSL, short for Digital Subscribers Line, employs an unused portion of your telephone line, so there's need to install another one into your home or office. Those living closest to the local exchange enjoy the fastest speeds.

SATELLITE

with Satellite Internet Access, you connect via the same satellite dish you use to receive TV programs. These systems can be one-way or two-way; Satellite is an option, although an expensive one. Just as bad weather may affect satellite TV reception, the same is true for Internet Service.

WIRELESS NETWORK

This relatively new service delivers speddy Internet Access via radio waves. WIFI is typically used in private wireless networks in homes and offices or in public places like airports or cafes.

Internet Terms and Definition

Internet Terms and Definition

·         Anti-virus Program

·         Software that Monitors a computer for viruses and eliminates them before damage occurs.

·         Applet

·         A small program, written in language called “JAVA” that can be placed in a web page and runs automatically when the page opens on your computer.

·         Applets are normally used for special effects.

·         Archive

·         A repository for software, data, or other materials to be saved and preserved. FTP sites are known as archives.

·         ASCII (American Standard Code for information Interchange)

·         A code used by computers to represent all the letters, numbers, etc on a computer keyboard.

·         Bandwidth

·         How much stuff you can send through a connection to the internet.

·         Baud Rate

·         The rate at which a modem (The Piece of equipment that canconnect your computer to the internet) can send or received information.

·         BBS (Bulletin Board System)

·         The computerized equivalent of a notice board.

·         Binary

·         A number system based on zeros and ones (0 and 1)

·         Bitmap

·         A graphic which is defined by specifying the colors of dots or pixels which make up the picture. Common types of bitmap graphics are GIF, JPEG, Photoshop, PCX, TIFF, BMP, and TGA.

·         Blogs or Blogging

·         A blog is a way for someone to present a running journal  for a wide variety of a readers.

·         Bookmark

·         A way for web browser user to mark a web page they want to return to later.

·         Bounce

·         The return of an e-mail message because of an error in its address.

·         Bug

·         A bud is programming error that causes a program or computer system to perform erratically, produce incorrect results or crash.

·         Byte

·         A measurement of data. Usually there are 8 bits in a byte- sometimes more, depending on how the measurement is being made.

·         CGI

·         A small program that takes information entered on a web page and does something with it, like turning a web form into an e-mail message. Examples of CGI programs are web site guestbooks or online shopping facilities.

·         Chain Letter

·         A form of SPAM which ask you to distribute the letter to many people.

·         Chat

·         A Form of real time electronics communication where participants type want to say, and it is repeated on the screens of all other participants in the same chat.

·         Chat Room

·         A place on the internet where people go to “CHAT” with other people.

·         Client

·         In Internet Terms, it’s an application that performs a specific functions, such as telnet or FTP.

·         Counter

·         A number seen on some web pages which indicates the number of visits the page has had

·         Cyber Space

·         A word used to describe the internet. The term was coined by science-fiction novelist William Gibson in 1984 in neuromancer.

·         Database

·         A collection of data records. On web databases, records may consist of web pages, or graohics or audio files, or newspaper files, or books, or movies, or press releases or almost anything from very general to very specific areas of interest.

·         Dedicated Line

·         This is a communication line that is used solely for computer connections

·         Dial-up

·         This is widely used method of accessing the internet.

·         Domain Name

·         The unique name that identifies an internet site.

·         Download      

·         The transfer of information from a computer on the internet onto your computer.

·         Electronics Mail

·         Messages sent from one person to another via computer.

·         Ethernet

·         A very common method of linking computers together.

·         FAQ(Frequently Asked Questions)

·         Documents that list and answer the most common questions on a particular subject.

·         Firewall

·         Firewalls are special computers or computer Programs that are set up on a network.

·         FTP(File Transfer Protocol)

·         Generally, any text that contains links to other documents.

·         A very common method of moving files between two computers.

·         GIF(Graphic Intechange Format)

·         A type of image file commonly found on the world wide web.

·         Giga Byte

·         A measure of stored information on a computer.

·         Hacker

·         Perform other destructive or illegal acts with computers and networks.

·         Header

·         Headers are not normally visible when reading emails or newsgroup.

·         Hits

·         The number of pieces of information downloaded from a web site.

·         Homepage

·         The main, or front, web page for a business, organization, person.

·         Host

·         May be the computer on which a web site is physically located.

·         HTML (Hypertext Markup Language)

·         The script Language used to create web pages.

·         HTTP (Hypertext Transport Protocol)

·         The Language used by computers on the world wide web to communicate one another.

·         Hyperlink

·         Hyperlinks are words, phrases, or graphic images that have URL’s hidden in them.

·         Hypertext

·         Generally, any text that contains links to other documents.

Browser

Browser

A browser is an application program that provides a way to look at and interact with all the information on the World Wide Web. The word "browser" seems to have originated prior to the Web as a generic term for user interfaces that let you browse (navigate through and read)text files online.

Technically, a Web browser is a client program that uses HTTP (Hypertext Transfer Protocol) to make requests of Web servers throughout the Internet on behalf of the browser user. Most browsers support e-mail and the File Transfer Protocol (FTP) but a Web browser is not required for those Internet protocols and more specialized client programs are more popular.

The first Web browser, called WorldWideWeb, was created in 1990. That browser's name was changed to Nexus to avoid confusion with the developing information space known as the World Wide Web. The first Web browser with a graphical user interface was Mosaic, which appeared in 1993. Many of the user interface features in Mosaic went into Netscape Navigator. Microsoft followed with its Internet Explorer (IE).

Network Backbone

Network Backbone

A backbone network or network backbone is a part of computer network infrastructure that interconnects various pieces of network, providing a path for the exchange of information between different LANs or subnetworks. A backbone can tie together diverse networks in the same building, in different buildings in a campus environment, or over wide areas. Normally, the backbone's capacity is greater than the networks connected to it.

A large corporation that has many locations may have a backbone network that ties all of the locations together, for example, if a server cluster needs to be accessed by different departments of a company that are located at different geographical locations. The pieces of the network connections (for example: ethernet, wireless) that bring these departments together is often mentioned as network backbone. Network congestion is often taken into consideration while designing backbones.

One example of a backbone network is the Internet backbone.

Internetwork

Internetworking

Internetworking is the practice of connecting a computer network with other networks through the use of gateways that provide a common method of routing information packets between the networks. The resulting system of interconnected networks is called an internetwork, or simply an internet. Internetworking is a combination of the words inter ("between") and networking; not internet-working or international-network.

The most notable example of internetworking is the Internet, a network of networks based on many underlying hardware technologies, but unified by an internetworking protocol standard, the Internet Protocol Suite, often also referred to as TCP/IP.

The smallest amount of effort to create an internet (an internetwork, not the Internet), is to have two LANs of computers connected to each other via a router. Simply using either a switch or a hub to connect two local area networks together doesn't imply internetworking, it just expands the original LAN.

The NSFNet

NSFNet

The National Science Foundation Network (NSFNET) was a program of coordinated, evolving projects sponsored by the National Science Foundation(NSF) beginning in 1985 to promote advanced research and education networking in the United States.^[1] NSFNET was also the name given to several nationwide backbone networks that were constructed to support NSF's networking initiatives from 1985 to 1995. Initially created to link researchers to the nation's NSF-funded supercomputing centers, through further public funding and private industry partnerships it developed into a major part of the Internet backbone.