A uniform resource locator, abbreviated URL (also known as web address, particularly when used with HTTP), is a specific character string that constitutes a reference to a resource.
In most web browsers, the URL of a web page is displayed on top inside an address bar. An example of a typical URL would be “http://en.example.org/wiki/Main_Page”.
A URL is technically a type of uniform resource identifier (URI), but in many technical documents and verbal discussions, URL is often used as a synonym for URI, and this is not considered a problem. URLs are commonly used for web pages (http:), but can also be used for file transfer (ftp:), email (mailto:), telephone numbers (tel:) and many other applications.