The KeyChain is an inbuilt utility comes along with MAC Operating System (OS X). Basically, it is a Password Management system for MAC users.
KeyChain saves login credentials for Websites, also it can store passwords for several applications and servers and much more. The best part is it can also store sensitive information such as credit card details, bank account details and much more.
Whenever you open an email account, website or network server or any password-protected Program/Application, KeyChain does the work for you which means you don’t need to type passwords in over and over again.
NOTE: You can start using KeyChain whenever you want, as it is created automatically when you log in your MAC OSX account for the very first time. The default password for your KeyChain is the same as you have your MAC account login Password.
By default Mac places KeyChain files in multiple locations as follow :
IMPORTANT :- The contents of all above said files are further combined into one single Application “KeyChain Access”. You can open KeyChain Access by going to following location.
Applications > Utilities.