PAM modules

PAM (Pluggable Authentication Modules) are a flexible system used in Linux and Unix-like operating systems to manage user authentication. They allow system administrators to define how users verify their identity—such as through passwords, fingerprint scans, or other methods—by configuring small, interchangeable modules. This modular approach enables consistent, customizable security policies across different services (like login, email, or file access) without altering the core system. Essentially, PAM simplifies and centralizes the process of controlling user access, making security management more adaptable and efficient.