What is iCloud Keychain?

What is iCloud Keychain? - illustrated definition card

iCloud Keychain is Apple's built-in password manager. It generates strong passwords, stores them encrypted, autofills them with Face ID or Touch ID, and syncs them across your Apple devices.

It lives under Settings → [your name] → iCloud → Passwords. It also stores passkeys and verification codes, and warns you when a saved password appears in a known data leak.