In the most simple sentence possible, a noun or prounoun would be followed by a verb: I am. David sat. The dog barked.
In reality, nouns and pronouns can be followed by just about anything. In your question, the noun "noun" is followed by the conjunction "or," and the noun "pronoun" isn't followed by anything (besides punctuation).
an appositive
A noun or pronoun after a preposition is called an object of the preposition. It typically follows the preposition in a sentence to show the relationship between the noun or pronoun and other elements in the sentence.
An appositive is a noun or a pronoun that follows another noun or pronoun in a sentence to identify or explain.Example: Don't leave your burger there, my dog, Artemis will steal it.The noun Artemis is the appositive for the noun dog.
In a prepositional phrase, the noun or pronoun that follows the preposition is called the object of the preposition.
An appositive. It provides additional information or clarification about the noun or pronoun that comes before it in a sentence.
adverb
The noun or pronoun that follows the preposition is called the object of the preposition.
Is a noun (or pronoun) that follows a linking verb and renames or explains the subject.
A prepositional phrase that modifies a noun or pronoun is an adjective prepositional phrase. An adjective prepositional phrase almost always follows the noun/pronoun it modifies.
A pronoun that renames is called a reflexive pronoun. It refers back to the subject of the sentence and emphasizes that the action is being done by the subject onto itself. Examples include "myself", "yourself", "himself", "herself", "itself", "ourselves", "yourselves", and "themselves".
A noun, a pronoun, or a noun phrase that follows another noun or pronoun to identify or describe is is called an appositive(a noun in apposition).Example: My son, the actor, took a job in New York City to be near my daughter, the musician.The noun phrases 'the actor' and 'the musician' are appositives.
A phrase that renames or describes another noun or noun phrase is known as an appositive phrase. Appositive examples:Noun appositive: Mr. Johnson, my neighbor, often gives me flowers.Pronoun appositive: The winners, you and I, have to pose for photos.