I don't get it? "Cognitive" usually refers to do with the mind, mental processes, thinking, or the brain. In ethics, it refers to whether or not something is a "statement" or can be "true or false". 

Another possible definition I've seen is whether or not ethical propositions express "beliefs"? How are these connected? 'Beliefs' can be true/false but knowledge can't? Or what's there point?

So I guess I have two questions.

1.) Why the lable cognitivism?

2.) How are the various definitions connected:(they are true/false vs they are beliefs).