I'm absolutely amazed that this isn't available somewhere else, so I thought I'd post it.

A URL can contain 3 basic elements:
1. The base url (e.g. http://www.sampleurl.com/directory1/index.php)
2. Variables
3. Anchors

You start with a URL.

Then you signify the beginning of variables with a question mark (?).

Variables are stated with a key=value syntax and are separated by an ampersand (&).
E.g: ?key1=value1&key2=value2

You cannot have multiple question marks in the URL. If you do all variables after the second question mark will be ignored.

The final piece is the anchor which must go on the end. This is denoted by a pound sign (#).

A final url looks like:
http://www.sampleurl.com/directory1/index.php?key1=value1&key2=value2#te...