lighting

Continuity, governed by the script supervisor, is designed to be invisible.

“When you do things right, people won’t be sure you’ve done anything at all.” ~ God Entity, Futurama S03E20

The gophers and the caterers.

WITHOUT YOUR FOOD, COFFEE, AND CIGATETTES YOU’D BE NOTHING!

Compositors. They’re the people who make the sometimes dozens of layers of different visual elements into one coherent whole. This includes integrating CGI with actual footage, but there’s a lot more to it than just that AFAIK. If they don’t do their job right things look fake as fuck but if they do you’ll never notice.