What does a common noun do?

A common noun serves to name general classes of items rather than specific instances. This means it categorizes people, places, things, or concepts in a broad manner without designating a unique identity. For example, the term "city" refers to any city collectively and not a particular one, unlike a proper noun, which would specify, such as "New York City." This distinction highlights the essential function of common nouns in language, allowing us to discuss groups and categories that share common characteristics, rather than pinpointing individual entities.