I think you mean 'Keychain Access'. This is the utility that allows you to change settings for your keychain. And the keychain can be used to store the majority of your passwords to allow quick, reliable access to programs, mail, internet sites, most anything that requires password access.
From Keychain Access Help:
'About Keychains
You can use a keychain to keep track of passwords for applications, servers, and websites; cryptographic keys and X509 certificates; or even sensitive information unrelated to your computer, such as credit card numbers or personal identification numbers (PINs) for bank accounts.
When you connect to a network server, open an email account, or access any password-protected item that is keychain-aware, your keychain provides the password so you don't have to type it.
You start with a single keychain, which is created automatically the first time you log in to your Mac OS X user account. Your default keychain has the same password as your login password. This keychain is unlocked automatically when you log in to Mac OS X and is referred to in Keychain Access menus as the "login" keychain.
You can create different keychains to store passwords for different purposes (for example, one for work and one for online shopping) or make a copy of a keychain so you can take it with you to other computers.'
Why would you want to disable such a useful tool?