Internet and modems

The Internet is a network of millions of computers all linked together through telephone lines and other telecommunications connection lines. When you are online, or connected to the Internet, you can use e-mail and instant messaging (IM), research information, read the news, shop and trade stock online, and/or just surf the Net. We are always becoming more and more interconnected.
The Internet includes many applications, but the main one is the World Wide Web. This is what most people think of when they think about the Internet. Imagine an endless spider web where digital documents are scattered around, living in different parts in the web. Each document has its own unique address, called a Uniform Resource Locator (URL). The documents are connected to each other through web strands, or links. Make the web into the worldwide computer network and the documents into Web pages, and you have the basic picture of the World Wide Web.

To connect to the Internet, you need some sort of Internet connection service. There are two basic kinds: Internet service providers (ISP) and online services. An ISP is a company that gets you connected to the Internet. You usually do this through a "dial-up" service, which means the data goes through the phone line. An online service, such as AOL and MSN, goes beyond the ISP. It actually comes with its own software, which includes a browser, e-mail, and Internet content limited to customers. When signing up with a connection service, ask about set-up fees, service rates, backup numbers in case the primary connection fails, connection speeds, and any additional charges. A good service rate is unlimited access for a flat rate, which means you pay a set amount of money every month for unlimited time online.
An Internet browser is a program that reads Web pages and translates them from hypertext markup language (HTML), a program code, to what you see on the monitor screen. The two best known browsers are: Microsoft's Internet Explorer and Netscape Navigator, which are both usually pre-installed. If you are using an ISP to go online, you still generally use one of the above browsers. Also if you go with an ISP, you need to get an e-mail account elsewhere. There are many options: e-mail programs, such as Microsoft Outlook, and free Web-based e-mail, from Yahoo! and Hotmail.

Modems, in short, download Web pages from the server. They convert digital data from a server into "phone line language," or analog/audio frequencies, and back again when they get to your computer. The final result is a Web page or e-mail. Most computers already are pre-installed with an internal modem, but if not, you can install one yourself. You can also use an alternative external modem. Generally, internal modems are cheaper and don't take up desktop space, but external ones are easier to install.

The standard modem speed as of 2002 is 56.6Kbps, also known as 56K. In theory, this means it is capable of dealing with 56,600 bits of data per second. However, in reality, the modem probably operates at a speed of 48K.
Technology is also providing new and faster digital-only modems, different from your typical 56K modem. These modems don't have to convert between the analog and digital signals. So all the time spent performing conversions before is now devoted to transmitting data. These new, fast connections include:

Integrated Services Digital Network (ISDN)

ISDN offers two 64K lines on the digital modem to reach speeds of 128K

cable modems

uses your cable television connection instead of the phone line. As a result, you need to purchase cable Internet access. Even though the connection is capable of the same speed each way, the upload rate (1.5 million bits per second or 1.5Mbps) is slower than the download speed (400 kilobits per second or 400K)

Digital Subscriber Lines (DSL)

One of the most popular alternatives to a traditional modem is DSL. DSL connections use the phone lines, but at a different frequency than voice communications, which allows you to surf the Net and talk on the phone simultaneously. With DSL, the speed can range from 1.5M to 8M, depending on the distance between your computer and the connection center.

However, all these devices are costly to install. Expect the installation costs of digital modems to go down as they become more mainstream.