Final answer:
The Security Accounts Manager (SAM) database in the system registry is used for local authentication methods in Windows operating systems, storing user and group credentials.
Step-by-step explanation:
The Security Accounts Manager (SAM) database is located in the system registry of Windows operating systems and is used for storing user and group information relevant to local authentication methods. This includes usernames, password hashes, and other security descriptors associated with local user accounts. The SAM database is crucial for the secure operation of a Windows operating system as it controls users' access to resources on the local computer by verifying their credentials when they attempt to log in.