Yup, you can also set up Steam to launch Big Picture mode at Windows boot, if you wanted to use the computer exclusively for gaming, and in addition, it's currently the best way to use a game controller on Windows, since when running in Big Picture it takes over all game controllers with its own input wrapper, which makes nearly any game controller work in a unified way with completely configurable controls. This is quite a big problem on Windows where a lot of controllers won't work without fiddly and often suspicious 3rd party driver packages and programs.

Additionally, Big Picture mode lets you remap controller buttons to basically anything you like (other buttons, keyboard keys, entire sequences of actions, mode shifting, overlay menus, different actions depending on if you press/double press/hold, etc). And, you can browse controller configurations that other people have made, too. Often there are lots of solutions for games that don't officially support controllers, and even in those that do, often there are improved mappings with added features like gyro aiming, or using a combination of gamepad and mouse input (all on the controller of course) to improve in game aiming.