: Files required by Windows or third-party players to play HEVC-encoded videos if the native support is missing.

: Stands for High Efficiency Video Coding (also known as H.265), a video compression standard that offers better quality at lower bitrates than its predecessor, AVC.

You can use 7-Zip on any computer, including a computer in a commercial organization. You don't need to register or pay for 7-Zip. Does 7z compress better than zip? - Microsoft Community Hub