I see. The keyring can store passwords and encryption keys for you. They are protected with your login password and stored safely via encryption. It’s like putting all your keys in a safe that just has one key. Every time you use an application for which you have stored a password for in the key ring, the key ring enters it for you. Beside the comfort factor that helps to counteract key-loggers and the like, as they need physical access to your key-ring data and your account password.
Normally, if you don’t have auto-login activated, the keyring is unlocked, when you login using your account’s regular password. Since you seem to have enabled auto-login on start-up (just a guess), the keyring has to be unlocked manually with your accounts password (once on first use for each session) .