What is Keychain and how does it keep my passwords safe?

Keychain is Apple's built-in password manager. It stores all your passwords, WiFi keys, and credit card information so your Mac can fill them in automatically. It's encrypted and locked with your Mac password, so only you can access it. You don't need to do anything — it works silently in the background.

Keychain is like a locked safe inside your Mac. When you enter a password once, Keychain asks if you want to save it. After that, your Mac fills it in automatically when you visit that website or open that app. All the passwords are encrypted and can't be read without your Mac password.