Help me to know element of URL

Hello dear friends I wanna know the meaning of url content of hyperlink as mine is

http://www.spreadfirefox.com/node&id=232203&t=1

http://www.spreadfirefox.com/node is ok

id=232203 is my ID number to identify my traffic :P

But what is meant by "t=1" this changes in every affiliate banner or button what this means... value of 't' changes like this according to banner or button t=305, t=318, t=312, t=306.

Thanks

Harpreet Singh Sahota.