What is the concept of an academic vocabulary?

Answer 1

There are many levels of language. For example, when you're with your friends you speak very casually. In class, your language is (or should be) a bit more formal and careful. In business or if you're addressing a group, you use more formal language. It's necessary to understand how and when to use the various methods of speech.

Answer 2

Using exactly the right word that paints and accurate picture.