Glossary
AppLocker
Windows application control feature that allows or denies executables, scripts, installers, DLLs and packaged apps per user or group.
AppLocker is an application control feature introduced with Windows 7 and Windows Server 2008 R2. Administrators define allow and deny rules by publisher, path or file hash for five rule collections: executables, Windows Installer files, scripts, DLLs and packaged apps. Rules can target specific users or groups, which makes AppLocker useful on shared machines.
It depends on the Application Identity service and is enforced in user mode, so it is not considered a security boundary against an administrator. Microsoft keeps it supported but recommends App Control for Business for new deployments, with AppLocker as a complement. Audit and block events are 8003 and 8004 in the AppLocker EXE and DLL log.