Authentication
Domain: Internet & Web
🎯 Motivation
Verifying who a user is. Usually with username + password, or tokens.
📋 Concrete Example
Authentication: user enters username alice and password secret123. Server checks: does this match the database? Yes. Authentication successful. User is Alice.
🔗 Analogy
Authentication is like showing your ID at a club - the bouncer checks your ID (password) against their records. If it matches, you are authenticated and can enter. The server authenticates users similarly.