OS X is designed to give you a safe and secure computing environment. The security of your Mac depends a great deal on using secure passwords in key areas.
A login password, also called a user password, allows the user to log in and access the information on the Mac. Privileges are limited by the type of user. An administrator user is required to perform many important tasks, such as setting certain system preferences, installing software, and administering standard users. For more information, see Set up users on your Mac.
Passwords in iCloud Keychain
Keeping track of passwords is hard, especially if you never use the same password twice and have multiple devices. iCloud Keychain keeps website and Wi-Fi passwords up to date across your Mac and iOS devices. It also keeps account passwords and settings that you add to Internet Accounts preferences up to date on your Mac.
When you need to create a new password for a website, Safari suggests a unique, hard-to-guess password and saves it in your iCloud Keychain. Safari fills it in automatically the next time you need to sign in, so you don’t have to remember it or enter it on any of your devices. For more information, see Set up iCloud Keychain.
Passwords for websites or Internet apps
If you need help with a password for a website, see the website’s help, or the account information on the website.
If you need help with a password for an app that connects to an account on the Internet or a network, see the documentation that came with the app, or online information that supports the app. For example, if you have a mail account with a service provider or website, see the documentation on the website or contact the provider. For more information, see the Apple Support article If Mail on your Mac keeps asking for your password.
Passwords in Keychain Access
Keychain Access stores passwords for various apps and services, and saves you the effort of authenticating separately for each of the items in your keychain. The keychain is secured by a keychain password, which is unlocked when a user logs in. For more information, see About your keychain password.
When you encrypt the information on your Mac using FileVault, a recovery key is created as a safeguard. If you forget your login password, you can use the recovery key to unlock the encoded contents of your Mac. The recovery key should not be physically stored with the Mac where it can be discovered. You can also have Apple store your recovery key. For more information, see Reset a login password.