The brain is a soft organ that is inside our head and is protected by the skull. The plural is ‘brains’.
The mind is what the brain can do for example: think, feel things, reason, understand etc. (stative verbs) The plural is ‘minds’.
idioms with the body part ‘brain’
Let’s look at some popular body idioms that contain the body part ‘brain’ or ‘mind’.
I’ve added the meaning and a picture example too.