User Account Control (UAC)—Definition

User Account Control (UAC) is a Windows security scheme dividing users into one of two groups: standard users and administrators. By default, all users operate as standard users. Standard users must have read/write permissions assigned specifically to gain write access to folders and files, and must gain administrator approval to install programs or perform system modifications. However, those users belonging to the administrators group can temporarily elevate their own permissions level to access all folders and perform administrative tasks such as assign permissions, assign privileges, and perform system modifications.