Reflect - Networks

While the term "computer networks" may elicit thoughts of system administrators and supercomputers, the reality is that computer networks are pervasive and can be found in a variety of unexpected places -- from the traffic lights in an intersection, to a DSL or cable modem, to a corporation's webserver, to a convenience store's closed circuit television.

Whenever you browse the web and type http://google.com/, your computer looks up which computer is named google.com, figures out which computers to route the connection through to reach google.com, connects to google.com's HTTP port, and proceeds to download the web page. Fortunately, all of the networking is automated so all you have to do is type the address and the network does the rest.

If you've ever noticed a particular website loads slower than others, it may be due to lag on a particular network segment. Since there is minimal lag on the other segments, those pages are not hindered; only connections which traverse the congested segment are slowed.

Whenever you check your email, you query a mail server. If you have a "webmail" account, your computer first looks up the site as described above, and then that server checks another computer to see if you have new mail. Sending mail involves a similar procedure, but the mail is routed to the recipients mail server instead.

If you've ever instant-messaged a friend, played a multiplayer game, browsed the internet, or read email, you've used computer networks. What other examples of networks can you think of?