what is the difference between 720p and HR episodes

hi to all,
my first time writing here..
can anyone tell me, so i can know once and for all, what is the diffrence from
the lost hr 700mb file and the lost 720p mkv file - what is better, what is
the
diffrence etc...
thanks a lot for the one who will ansewer that..

696320 pixels per frame. hope that helps.