Depends. If your output device is a local monitor, you usually need some kind of video adapter (you could also write your renderings to a file, networks stream, printer, ...).
But if you want it to be visible on the screen, you copy (or let the operating system copy) your prerendered image to the video memory. In that case, the only thing the video adapter does is to output the image data to the screen.
In hardware rendering, you do the same, the difference is that you don't first use the CPU to do the rendering work but some hardware accelerated mechanism. But the stuff that happens after rendering is exactly the same with the same hardware parts involved. That's why it's usually (or was at least at some point) called hardware accelerated rendering.
Edited by rnlf, 15 July 2014 - 09:30 AM.