Collective nouns refer to a group of people, animals, or things considered as a single unit. Examples include:
* Team (a group of people)
* Flock (a group of birds)
* Army (a group of soldiers)
"Word" is a singular noun, meaning a single unit of language. It can be used in the plural ("words"), but it doesn't inherently refer to a group.
Let me know if you have any other questions!