Proper noun: A noun that gives a special or particular name to a person, place, animal or thing is called a proper noun. A proper noun is a special name. It refers to the name of a single person, place, animal or thing. It gives us the actual name of the person, place, animal or thing. The actual names of people, states, streets, rivers, oceans, countries, companies, institutions, churches, and more are proper nouns.
A proper noun always begins with a capital letter, wherever the word may be in a sentence.
Person - Peter
The name Peter is the name of a particular person and not a general name like 'boy'. Peter is a proper noun.
Place - New York
The name New York is the name of a special city. It is not a general name like 'city'. New York is a proper noun.
Animal - Seabiscuit
The name Seabiscuit is the name of a special and famous horse (animal). It is not a general or common name like 'horse'. Seabiscuit is a proper noun.
Thing - Peacock Throne
The name Peacock Throne is the name of a special throne or chair. There is only a single throne of that name. It is not a common throne or chair. The Peacock Throne is, therefore, a proper noun.