Why do we use nouns?

Nouns refer to people, things, concepts, and other objects around us in the world. They are the original and central building blocks of language. Very young children, for example, will use nouns as though they were entire sentences - they'll say "milk" or "dog" when they mean "bring me some milk" or "look at that dog. Only later do they learn how to use verbs to specify actions relating to nouns, or use adjectives/adverbs to provide descriptions.