URIs

A URI (Universal Resource Identifier) is a sequence of characters that identify the World Wide Web request being made. Sometimes referred to as a URL (Universal Resource Locator) or URN (Universal Resource Name), with extremely subtle differences, we shall use the term URI for consistency with PHP's internal naming conventions.

A simple URI https://www.example.com/colour/red is made up of the following parts:

• https - the URI scheme / protocol being used to make the request
• www.example.com - the host (otherwise referred to as the hostname)
• /colour/red - the path

A complex URI https://henry:[email protected]:8301/colour/red?sort=price&filter=new#options is made up of the following parts:

• https - the URI scheme / protocol being used to make the request
• henry:s3cr3t - the user info
• www.example.com - the host (otherwise referred to as the hostname)
• 8301 - the port
• /colour/red - the path
• sort=price&filter=new - the query or querystring
• option - the fragment