Slack is a team messaging platform made by Slack Technologies, LLC, a Salesforce company. Work in Slack happens in channels: shared spaces for one topic, project or team, where members write messages, share files and search earlier conversations.
A company creates a workspace and adds its staff. Channels can be public or private, and direct messages connect two or a few people. Slack Connect shares a channel with people at another organization, such as a vendor, a customer or a partner; each side decides who can join and what they can see. Video calls, Canvas documents and Lists work in the same app. More than 2,600 apps in the Slack Marketplace, and the Slack APIs for a company's own tools, connect other software, so that its notifications and actions appear in channels. Workflow Builder automates routine tasks, and Slackbot, an AI assistant inside Slack, answers questions and runs tasks.
Slack is a hosted service with a free plan and paid plans charged per user each month, with a lower price for annual billing.