What term refers to the interaction or activities involving two or more people?

The term that accurately describes the interaction or activities involving two or more people is engagement. Engagement encompasses a broader range of interactions than just communication or collaboration, highlighting the active participation and involvement of individuals in a shared experience or activity.

Interaction is a more general term that signifies any form of reciprocal influence between individuals, but it doesn't necessarily imply active participation or contribution. While collaboration focuses specifically on working together towards a common goal, engagement encapsulates the fullness of participation, making it the most suitable choice in this context.