User Account Control (UAC) is a Windows security feature that reduces the risk of silent privilege escalation. When a program needs administrative rights, UAC can prompt for consent or credentials and, on many systems, runs standard processes with a filtered token instead of full admin privileges.
UAC matters because many attacks begin with code execution as a normal user and then try to cross the boundary into administrator-level access. Exploit chains, malicious installers, and UAC bypass techniques all aim to defeat that gate or trick a user into approving elevation. Defenders use UAC alongside least privilege, separate admin accounts, and application control to make local exploitation less useful. In practice, a flaw that only yields user-level access may be far less dangerous than one that can bypass UAC and gain control of the host.