Keychain Access: Keychain Access overview
Keychain Access is an OS X app that stores your passwords and account information and reduces the number of passwords you have to remember and manage.
When you access a website, email account, network server, or other password-protected item, you may be given the option to remember or save the password. If you choose to save the password, it’s saved in your keychain so you don’t have to remember or type your password every time.
Because Keychain Access securely stores and retrieves your user names, passwords, and other information, you can make individual passwords more complex and difficult to break. This can make your individual accounts more secure.
You can also store any type of sensitive information in Secure Notes.
You can also use Keychain Access to manage certificates, which are issued by trusted organizations to validate websites, digital documents, and other web-based materials.
Keychain Access works in collaboration with iCloud keychain, which lets you share keychains with your other devices. iCloud