Quick Assist, originally known as Windows Remote Assistance, is a feature of Windows XP and later that allows a user to temporarily view or control a remote Windows computer over a network or the Internet to resolve issues without directly touching the unit.
It is based on the Remote Desktop Protocol (RDP).
It is complemented by Get Help, a feature introduced in Windows 10 that enables the user to contact Microsoft directly but does not allow for remote desktopping or screen sharing.