• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

How a Firewall Works

Computers communicate by sending electronic messages to each other. On the Internet, millions of computers send messages back and forth, so each computer on the Internet has a unique address, called an IP address, that’s used to distinguish that computer from all the others. When a message is sent from one computer to another, it’s divided into small pieces, called packets. Each packet contains the IP address of both the sending computer and the destination computer. These packets travel separately through the Internet until they reach the destination computer. Once all the packets arrive, they’re reassembled into the original message.

When a computer is connected to the Internet, it constantly sends and receives packets of information. Typically, this information is something useful. For instance, Web browsers receive packets that contain Web pages, and e-mail programs send packets that contain e-mail messages.


PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint