We have talked a lot about (intersectional) social categories as collectivities.
(Racial/ethnic; Class; Gender; Disability; …)
These social categories define shared experiences, cultural dispositions, societal expectations, opportunity structures, etc.
Groups and organizations are (usually) considered a different type of collectivity.
(Family; School; Friend group; Office; …)
Groups and organizations are made up of people who are oriented around a place or goal, and who are likely to interact with one another.