whats the diffrence between _top and _self ?

Question

both gives d same result

Answer 1

Those are pretty useless now. They were used in the time of frames and before CSS came in. If you understand how frames work (don't use them. They are obsolete in HTML5) you will understand how _self, _top and _parent work. The only useful - I think - one left now is _blank. It opens the target in a new window or tab.