Installing program

Hi members i am new to os x tiger can anyone tell me how to completely uninstall program each and every bit so that none of it's file remain in hard drive.
how to defragment hard drive

To uninstall an app completely (absolutely not necessary to do so btw), you can use AppZapper, a third party utility.

To defragment (many say its not needed, but I find a performance improvement), use iDefrag, again, a third party utility.

Another alternative, this one free, is AppDelete. I personally use AppZapper, but find AppDelete to be just as effective.