On a laptop, if you have a graphics chipset can you upgrade to graphics card?

Pretty much, the whole thing is integrated which means there's no means of an actual upgrade. Laptops have that disadvantage against desktops in which a lot of stuff is not customizable. It's important to not be railed in by the first laptop the clerk shows you (which usually sucks) and look carefully at the options, so as to not get stuck with undesirable specs. That said, if you don't really need the "bring anywhere" aspect of a laptop, a desktop offers a broad amount of options and it's really what anyone who wants high def video and gaming should aim for.