There are also extras: video files can be rotated or even flipped. This is really useful if any filming was inadvertently done 90º off normal. Then there is also Screen Recording which can include audio. This makes it easy to create a video of anything you want to show on screen - it doesn't have to be a big production: uses include making a simple 'how to' to send to a friend, or sending a video of when a problem occurs to your IT dept.
Incidentally, Quicktime Player is a misnomer; both versions can record video or audio.