Attribute keys and values

- The keychain allows you to store different types … or classes of data. … We'll be focusing on passwords. … And we can also use that same class for text data … like notes or credit card numbers … which you always want to protect. … These classes map to tables in the encrypted database … where Keychain stores the data. … For each class, there are various attributes that map … to columns in the tables. … The classes are generic password, Internet password, … certificate, key, and identity, which is a combination … of certificate and key. … The attributes vary from one class to another … but there's a lot of crossover too. … When we're writing to the keychain, you specify … the class and the attributes to store. … The attributes help you store more data but can also help … when it's time to find the data. … Like searching in a database, you tell the keychain … which item or items you're looking for by specifying … the attributes to match. … Also when you're updating or deleting from the keychain …