Over-the-Shoulder (OTS) Credentials
Whenever standard users attempt an administrative task, such as software installation, they will be prompted for an administrator password. If they know their local administrator password they may enter it then or ask an IT administrator for assistance. This process is called over-the-shoulder (OTS) credentials. IT administrators can disable this feature, in which case the user is simply informed that they do not have the permission to perform the operation.
Admin Approval Mode: Right Privilege at the Right Time
To help protect administrators while doing non-administrative operations, the Windows Vista team has devised the Admin Approval Mode feature. This feature allows administrators to perform normal day-to-day tasks such as checking e-mail or browsing the Web while running with a standard user token. If administrator privileges are needed for an operation, the administrator will be notified and asked to provide either consent or credentials, depending on system policy settings. The Windows Vista team calls this approach "right privilege at the right time." There's no more switching back and forth between standard user and local administrator, juggling two user profiles.