Precise language is using exact, specific words. Writers use precise language to give readers particular images in their heads. Precise language makes writing clear and easy to understand.

Here is an example of vague word choice:

Henry told his friends there would be cake at his birthday party.

What kind of cake? The writer needs to be more specific.

Henry told his friends there would be chocolate cake with vanilla icing at his birthday party.

Readers now have a vivid image as the word choice appeals to their sense of taste.