URL (Uniform / Universal Resource Locator) is a string which suggests where can be a file found on the internet. It is thus a reference or an address of a WWW (World Wide Web) resource.
The URL contains the protocol prefix, port number, domain name, sub directory name and file name.
From the example given above, we can separate different parts of the URL as follow:
|Domain name(Root Directory)
|File name or a resource name
If a port number is not stated in the address, port 80 is used as the default.
The term “Web address” is a synonym for a URL that uses the HTTP / HTTPS protocol. Sometimes a term URI (Uniform Resource Identifier) is used as a synonym for URL, but it is not correct as URL is a type of URI and not a synonym of URI.