What do collective nouns differ from plural nouns?

Collective nouns are Words used to group people or things taken together as one whole, such as a crew of workers, a chain of restaurants, or a litter of kittens.

Plural nouns are Words for more than one person, place, or thing, such as a worker or two workers; one restaurant or three restaurants; and a kitten or four kittens.

Collective nouns can be singular or plural; for example, two crews of workers, several chains of restaurants, or the mother has had two litters of kittens.