Keychain

From Mac Guides

A Keychain in Mac OS X is a password storage system that stores passwords for such things as email, websites and disk images. It can also be used by third party applications to store passwords. This system enables users to avoid having to enter their passwords multiple times, yet store them in a secure way.

Keychain passwords can be accessed through the Keychain Access application located at /Applications/Utilities/Keychain Access, after entering your keychain password (usually your user account password). Secure notes can also be added, to securely store your own passwords or notes.

For backup purposes, your user keychain is located in ~/Library/Keychains/, where ~ is your home folder.