It is a worldwide WAN.
The Transmission Control Protocol divides each message into small pieces (packets), numbers them, and hands them to the
Internet Protocol. This protocol takes care of sending these packets. Each one is sent separately and contains IP address and the number of the piece.
The IP address has the form of four numbers, separated by dots, like 18.104.22.168. The first one/two/three of these numbers are the network number, the last three/two/one the host number, depending on whether the number belongs to a class A/B/C subnet.
Domain Name Service. Since IP addresses are difficult to remember, each server has also a domain name like "www.fc.edu" or "mycompany.com", something separated by dots (but the parts between the dots don't correspond to the parts between the dots in the IP addresses). "de" or "com" is the top-level domain, the other one, two or three parts are sub-level domains. Common top-level domains are:
How does data find the corresponding address? Gateways are computers for exchanging data between different subnets. They use so-called routing tables. The way data takes between two fixed points differs over time, depending on which ways are currently unavailable or congested. Even part of the same page may go over a different continent than another.
Uniform Resource Locator, like "http://www24.brinkster.com/prisnerich/CPT105/CPT105.html" shows you the protocol used (http), the domain name (www24.brinkster.com), and the path (prisnerich/CPT105/CPT105/CPT105.html)---folder and subfolders---where the page you are looking for (CPT105.html) is located on the server.
In other cases, when you don't just look for an existing page but let yourself create a special page using scripts, you have protocol, domain name, and some query.
MIME means Multipurpose Internet Mail Extension is a way of describing the document's type. Here are examples:
|MIME-type||document extension||document type|
|image/jpeg||jpeg or jpg||JPG Picture|