It should be a large piece of hardware stuck horizontally in the motherboard. But really, your question is more ambiguous than you think. Either give us more details or just look up pictures of graphic cards.
One issue you might have is that it is an IGP or onboard and there is actually no dedicated card sticking out. Just give us some context if you want a better answer
Depends if it is built into the Motherboard (Integrated Graphics) or a Card. Easiest method, where are you plugging in the Video Cable, open the case, there it is!
It should be a large piece of hardware stuck horizontally in the motherboard. But really, your question is more ambiguous than you think. Either give us more details or just look up pictures of graphic cards.
One issue you might have is that it is an IGP or onboard and there is actually no dedicated card sticking out. Just give us some context if you want a better answer