How is a rendering platform different from a web browser

What exactly is a rendering platform, is it different from a web browser or part of it or a layer beneath the browser?

As far as I understand a rendering platform is the one which actually parses the content and displays it on the screen, am i right? If so, what does a browser do? Does it just provide the interface which has menu bar etc. and developer tools? Also what are some examples of good rendering platform?

Can someone please explain in a simple way?