I don't understand noun pronounce that

Noun - The name of any person, thing, place, animal, emotion,etc. is known as "noun". For ex:- Ram, Pencil, School,etc. Pronoun - The word which is used instead of a noun, known as "pronoun". Ex:- Ram is my brother. He is very smart. Here, Ram is a noun and he is a pronoun that has come for noun Ram.