Keep your computer secure
To protect your computer, macOS uses digital certificates to verify the identity of the websites, servers and other entities you communicate with. You can use Keychain Access to manage these certificates.
You can find all your passwords, passkeys and verification codes in the Passwords app 
on your Mac. See the Passwords User Guide.
To explore the Keychain Access User Guide, click Table of Contents at the top of the page or enter a word or phrase in the search field.