Noun and Noun Phrase can be used almost synonymously. A Noun suggests a single word that is an object or idea. The term Noun Phrase suggests more than one word, in effect, a group of words functioning as a noun.
Both can function in a sentence as either subjects, direct objects, objects of prepositions or indirect objects.
Examples of nouns include: horse, Paris, loyalty, description, desk.
Examples of noun phrases include: the big black book, her beautiful hair, the words that saved her.
A noun phrase can be very complex, or simple. Typical constructions involve an article (the, a or an) an adjective, and then the noun; or, a noun with a subordinate clause or prepositional phrase modifying the noun.
A noun is a person, place, thing, or idea. Words such as boy, drum, house, bike, glory, are all examples of nouns. A noun phrase is a bit more complicated. They are called noun phrases, because usually a noun or pronoun (I, you, he, she, it, they, we, me, him, her, it, us, them) is at the head of the phrase. Usually, the noun or pronoun are with a set of modifiers. There are different kinds of modifiers: determiners, which are usually placed before the noun (this, that, the, five, a, etc.); adjectives, such as colors; complements; and modifiers, which help to describe the noun more--such as the handsome man.
So, a noun phrase would look like this:
The bold and the beautiful...
The boisterous man yelled...
A noun, of course, is a word that refers to a person a place or a thing. So in the sentence I just wrote, the words "noun," "word," "person," "place," and "thing" were all nouns.
A noun phrase is either a word or a set of words that has the same function as a noun. A noun phrase must have either a noun or a pronoun in it. An example of a noun phrase can be found in the following sentence:
"All of the batters who faced him hit at least one ball for six."
In this sentence, the phrase "all of the batters who faced him" is a noun phrase because it contains a noun (batters) and the whole phrase tells us who did the action in the sentence.