When you submit a request, you can pass parameter values in the request with a special coding technique that allows them to convey information in the URL that is reflected into special properties in the request object.
The question mark (?) is the control sequence introducer for this. Sometimes these values are referred to as the query or search portion of the URL when they are accessed as properties of an Anchor, Url, or Area object in the client.
The properties are then added as a name=value pair with multiple name=value pairs separated by an ampersand (&) character.