PC Hardware

The Internet

The Internet, also known as "the Net," is the most WAN in the world-a network of networks working together. This relatively new communication technology has begun to affect our lives as significantly as television and the telephone. When most people talk about using the Internet, they talk about which Web sites they have visited or who they've met online.

Most LANs make use of passwords and other forms of security, but the Internet is one of the most open networks in the world. Some common Internet uses include communication; locating lost friends and family; researching information for school or work; and locating businesses, products, or services (such as travel). The Internet can be your most valuable resource for virtually anything and everything.

A thorough knowledge of the Internet and how it works is not a requirement of A+ Certification. However, as an A+ technician, you might find that it becomes the single most valuable information tool at your disposal.

Internet Basics

The Internet is really a collection of services. Let's take a look at the most important services and the major concepts behind them.

The World Wide Web (WWW)

When people say they were "surfing" the net, they were probably visiting the collection of hyperlinked Web sites known as the World Wide Web. These Web sites are located around the world, and their numbers continue to grow by the thousands every day. Each Web site within the World Wide Web has a unique address called a Universal Resource Locator (URL).

The World Wide Web (usually abbreviated as "the Web") is not the Internet-it is only part of the Internet. Although it is currently the largest, most popular, and fastest growing part of the Internet, it represents only a fraction of Internet services available that include FTP, Gopher, and Telnet.

Electronic Mail (E-mail)

Electronic mail, usually known as e-mail (sometimes spelled E-mail or email), is the most commonly used function of the Internet, allowing users to send and receive messages (and files) electronically to and from millions of people all over the world. Electronic mailing lists allow users to join group discussions with people who share their interests. Like regular mail (also called snail mail), e-mail is also sent to an address (a virtual one).

File Transfer Protocol (FTP)

The File Transfer Protocol (FTP) is a special application used for uploading and downloading files to and from the Internet.

Transmission Control Protocol/Internet Protocol (TCP/IP)

The Transmission Control Protocol/Internet Protocol (TCP/IP) is the language (network protocol) used by computers to talk to each other over the Net. TCP/IP has also become a common protocol for LANs. Regardless of which operating system or software is being used, your commands travel through the Internet in TCP/IP format. The services of the Internet and the World Wide Web could not be provided without TCP/IP.

Internet Protocol (IP) Address

Each machine on a network is given a unique 32-bit address. These addresses are normally expressed in decimal values of 4 bytes, separated with periods; for example, Without a unique address, there would be conflicts and chaos. This is the same concept as the hardware addresses discussed in Tutorial 10, Lesson 2: Configuring Expansion Cards, except that it is a software address. It designates the location of its assigned device (usually a NIC) on the network.

Internet Service Providers (ISPs)

Internet service providers furnish the connection between dial-up (modem) users and the Internet. While some are big names with millions of users, there are many more that serve local areas with both dial-up and hosting plans.

Uniform Resource Locators (URLs)

As mentioned, the Uniform Resource Locator is the Web's address system. To access a Web site, the user must enter the designated URL on the network. Each URL begins with the character sequence "http://". The letters "HTTP" are an acronym for the Hypertext Transfer Protocol, which identifies the Web site as an address. The rest of the URL is the name of the site. For example Microsoft's URL is http://www.microsoft.com. (Because it is universal, it is seldom necessary to first type the characters "http://" when typing a URL in a search engine; most engines take it for granted.)


An Internet domain is a site with a common general interest or purpose, often run by a single firm or institution. The domain suffix gives a general idea of the site's purpose: .com, for businesses, or .edu, for educational institutions. The following table lists common Internet domains.

Domain Description
.com Commercial organizations
.net Networks (the backbone of the Internet)
.edu Educational institutions
.org Nonprofit organizations
.gov US Government nonmilitary institutions
.mil US Government armed services
.xx Two-letter country code.

Domain-Name Server

A domain-name server is a computer that matches IP addresses with domain names. The domain name makes it possible for you to use the easy-to-remember domain name BigCompany.com without having to memorize the string of numbers in the IP address.

Getting Connected

These days, many computer professionals spend a lot of their time getting clients online.

The first thing you need to do to get a client connected is to make sure they have a service provider (we're assuming your client has a computer and a modem). Most people connect to the Internet using independent ISPs that provide local community-based service to Internet users, but popular national ISPs such as The Microsoft Network (MSN) are useful if you travel because many of them have 800 numbers for dial-up access, or many local numbers throughout the country. Local ISPs are great for customers who are looking for a cost-effective company that offers local (including technical) support.

You also need to consider which browser(s) to use. Most ISPs (especially the local ones) provide only the connection or gateway to the Internet. Others provide their own browser software package. Most ISPs allow you to use your choice of browsers. Some local and national ISPs provide a startup CD that includes their recommended browser, as well as FTP tools and other Internet utilities. From time to time, Web surfers will encounter pages that work only with a specific browser. In this case it might be necessary to install both browsers.