Yesterday, i put my animation to render, it went fine. But one thing that bothers me is: What is the Render and Preview? I actually discovered that the Render is something like the quality, so i keep it on 128 because it is fast and the quality is great for me. But what is Preview? And what should i keep it on? Any help would be appreciated.
I use the CUDA with GPU Compute rendering (cycles). I'm new to Blender so i may seem silly.


Yes, when the preview samples has been completely rendered it will stop rendering and thus, the resources used while rendering will be freed up to do other things.
– Tobias Einarsson Nov 08 '17 at 09:31