Communities are clusters of entities that are tightly connected in your case graph. They are useful when you are looking for subgroups (networks that “stick together” in the data).
After a big upload or UFDR processing run, use refresh communities (or your deployment's equivalent) so clusters reflect the latest graph. Expect layouts to shift; that usually means the model is catching up to new material.
Some products can generate a short narrative about what ties a community together. Treat that text as a briefing aid, not evidence: read the underlying mentions and files before operational or charging decisions.
Community views can surface sensitive associations. Share screenshots or exports only through approved channels and redact per policy.