What is a USB video card and can it be used with any laptop?

I have an integrated memory laptop so i cannot add memory to my laptop. But ive been hearing about a USB video card. would i be able to use this?



this is to be able to play sims 3. I think my computer will run it but probably not that well.|||A usb video card does exist, but it is not for what you want to do with it. it is for doing stuff with multiple monitors and stuff like that, not playing games.