How URL's work
URL stands for Uniform Resource Locators, and is formally defined in rfc 1738.
A URL is essentially an address of a location on the internet. The address is reachable via a protocol, such as
http or ftp, which is also specified in the URL.
URLs typically contains a domain adress, such as "cnn.com", which is
resolved by a domain name system (DNS).
The DNS performs a mapping of the domain name, to a physical IP adress. This adress is used to route the request to the
right location. The domain name is simply a way for people to easily remember the address, and to allow requests to be
routed to various IP Adresses using the same domain name (redirection).