Extending abilities or improving performance. These different languages are able to represent my knowledge of Newton's law to different degrees of precision. Let's take natural language processing as an example. The speaker has something on his mind which he wishes the hearer to know. The problem of understanding language is the problem of understanding ideas.
Understanding requires making inferences.
John went to a store. He picked up some toothpaste and went to the check-out counter. He paid the cashier and left. I got a new TV at Macy's. John thinks vanilla.