WHAT IS PROPER AND COMMON NOUNS
Proper noun is the name of a particular place or person. A proper noun would name a specific item. Also, it will begin with a capital letter no matter where it occurs in a sentence.
Instances of the same are Jack, New York, Walter Hudson, etc.
Now, there are nouns which name people, places or things in general. These nouns do not talk about any one name in particular. Therefore, these nouns are known as common nouns.
Instances of the same are girl, pen, book, etc.