In order to help you protect your wallet against any kind of fraud and hacking incidents, MetaMask allows you to encrypt your wallet with a MetaMask sign in password. This password helps you to access your wallet as and when you need to. This wallet password is created at the time you first set up your wallet or at the time you import or set up your wallet. It is pretty easy to complete the MetaMask sign in process if you have the correct password with you.