Microsoft Office Tutorials and References
In Depth Information
Data Communications
Look at the computer ad in Figure 1. Is this computer networked? Can it be networked?
Why or why not? Your answer should be that the computer is not currently part of a net-
work but does include an integrated network adapter card. With the appropriate network
software, this computer can be connected to a network.
Telecommunications means communicating over a comparatively long distance using a
phone line. When it is not possible to connect users on one network, then telecommuni-
cations allows you to send and receive data over the telephone lines. To make this con-
nection, you must use a communications device called a modem . A modem, which
stands for mo dulator- dem odulator, is a device that connects your computer to a standard
telephone jack. The modem converts the digital , or stop-start, signals your computer out-
puts into analog , or continuous wave, signals (sound waves) that can traverse ordinary
phone lines. Figure 26 shows the telecommunications process, in which a modem con-
verts digital signals to analog signals at the sending site (modulates) and a second modem
converts the analog signals back into digital signals at the receiving site (demodulates).
Figure 26
Using modems to send and receive a memo
sending site
receiving site
Most computers today come with a built-in 56K modem. The number 56 represents
the modem’s capability to send and receive about 56,000 bits per second (bps) . Actual
speed may be reduced by factors such as distance, technical interference, and other
issues. This speed is adequate for Paik employees to connect to suppliers at other loca-
tions around the world.
The Internet
The Internet was originally developed for the government to connect researchers around
the world who needed to share data. Today, the Internet is the largest network in the
world, connecting millions of people. It has become an invaluable communications chan-
nel for individuals, businesses, and governments around the world.
The first Internet experience most people have is to use electronic mail , more
commonly called e-mail . This is the capability to send a message from one user’s com-
puter to another user’s computer where it is stored until the receiver opens it. The vast net-
work of networks that make up the Internet pass the message along through electronic
links called gateways . E-mail has become such an integral part of business that you know
you must recommend it to Mr. Paik. Your recommendation will list its advantages: speed
and ease of communication with vendors and customers, lower postage costs, lower long-
distance charges, and increased worker productivity.
Another benefit of using the Internet is the emergence of the World Wide Web , some-
times referred to simply as the Web . The Web is a huge database of information that is
stored on network servers in places that allow public access. The information is stored as
text files called Web pages , which can include text, graphics, sound, animation, and video.
A collection of Web pages is called a Web site . Figure 27 shows a sample Web page.
The Internet:
World Wide
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