how do somebody find you in their tracker? how does a tracker work? if you have a website how do they know its your website by their tracker?

Trackers are basically things that you put on your site that keep track of how many visitors came to your site, how long they stayed, what browser they used, how they found you, and much more. I recommend:

http://www.sitemeter.com
http://www.extreme-dm.com/tracking/

http://awstats.sourceforge.net/ - theres also awstats. But you need cgi access for it.