UAC, or User Account Control, is a security feature in Windows operating systems that helps protect your computer from unauthorized changes and malicious software. It works by notifying you when a program or action requires administrator-level permission, allowing you to choose whether to allow or deny it. This helps prevent potentially harmful programs from making changes to your system without your knowledge or consent. UAC is an essential tool in keeping your computer safe and secure, giving you peace of mind while using your device.