A proof of concept is something that shows the product is viable. That the solution you're attempting is tractable. An MVP is the minimal product where people will pay you for your solution.
To clarify, a POC proves that you can actually do it. So if you want to build a service to create 3d html5 drawings of famous buildings, you might do a POC to prove that you can actually draw complex images in 3d.
The mvp might be the ability to create simple 3d drawings of regular houses, or maybe one famous building.
