Communication OS is team messaging that sits next to your data rather than in a separate app.
What it covers
Channels for topic or team conversations, direct messages and group DMs, threads on any message, and saved items for things you need to return to. Announcements are one-to-many posts for things everyone must see.
Why in-platform messaging is useful
Because it shares the data layer, a conversation can reference a deal, a task, or a candidate as a real object rather than a pasted link. Discussion stays attached to the thing being discussed.
Search and discovery
Browse public channels, search messages, and find people through the directory. Anything you can see, search can find; permissions apply to search results the same way they apply to everything else.
Slack
If your team lives in Slack, connect it rather than replacing it. See Slack integration. Notifications, approvals, and Cortex answers can flow into Slack channels and DMs.
Tip: Pick one place for a given kind of conversation. Teams that run both Communication OS and Slack for the same purpose end up with half their history in each.