Start with the smallest place that lets people work together. A quick exchange can stay in chat or around a meeting. Create a Team when the work needs a recognizable purpose, recurring participation, shared context, and owners who can maintain it over time.
Document collaboration usually moves through stages: personal draft, short review, team collaboration, and publication.
Use Loop while a group is shaping ideas. Choose a shared workspace for ongoing group work, and publish approved information in a managed location.
Microsoft Teams is a workspace for people who work together. Start with a chat or meeting for a quick exchange. Create a Team when the collaboration needs a shared purpose, context, and ownership that lasts beyond one conversation.
Microsoft 365 collaboration tools overlap on purpose. The right choice depends on the relationship between the people involved.