Uniform Resource Locator
A uniform resource locator (URL) is a reference to a resource that specifies the location of the resource on a computer network, and a mechanism for retrieving it.
(TO DO: expand, organize, cross-reference, illustrate.)
Example
A typical URL has the form:
http://www.example.com/index.html
The above example indicates:
- The protocol type (http)
- The domain name (www.example.com)
- The specific web page (index.html)
Web servers commonly recognize index.html as a default file name.
URL is specific type of URI
A URL is a specific type of uniform resource identifier (URI). Many people use the two terms interchangeably.
A URL implies the means to access an indicated resource, which is not true of every URI.
Uses
URLs occur most commonly to reference web pages (http), but are also used for file transfer (FTP), email (mailto), database connectivity, and many other applications.
Browsers
Most web browsers display the URL of a web page above the page in an address bar.