Slack is a cloud-based team collaboration platform that centralizes workplace communication through organized channels, direct messaging, and integrations with thousands of third-party tools. Originally launched in 2013, Slack transformed how modern teams communicate by replacing scattered email threads with searchable, threaded conversations organized around channels for topics, projects, or teams. The key mental model: channels are conversations with context — unlike email or basic chat tools, Slack preserves the full history of discussions, decisions, and shared files in organized spaces where the right people can find what they need, when they need it, without hunting through inboxes or asking "who knows about this?"

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