Your link is useless without your Ebay login details (don't post them!) so I'll have to ignore that part of your post.
All laptop motherboards come with GPU attached since it's not a removable component, same with the sound chip.
Some laptops have a second, more powerful, "discrete" GPU which is removable, but the Aspire 4755G doesn't have one of those.
In the case of the the Aspire 4755G, the Intel GPU is integrated with the Intel CPU so it's actually an "APU" (Advanced Processing Unit).