Question

what is common noun​

Answer 1

$\huge\fcolorbox{black}{black}{answer}$

A proper noun is a noun that identifies a single entity and is used to refer to that entity, such as London, Jupiter, Sarah, or Microsoft, as distinguished from a common noun, which is a noun that refers to a class of entities and may be used when referring to instances of a specific class. 

Answer 2

Answer:

A common noun is the generic name for a person, place, or thing in a class or group. Unlike proper nouns, a common noun is not capitalized unless it either begins a sentence or appears in a title.