How are vivid nouns different from non vivid noun?

Vivid nouns (also called exact nouns or specific nouns) are more specific than general (non vivid) nouns. Vivid nouns are used to make the meaning clearer or more interesting. For example:

A man called you today.
Or,
My teacher called you today.
Or,
A contractor called you today.
Or
That crazy neighbor called you today.

Vivid nouns give the listener (reader) a better idea of what is taking place.