What is Microsoft Teams?

Microsoft Teams is the chat, meetings, and collaboration hub of Microsoft 365. People often describe it as "Slack plus Zoom plus a file workspace," and that's a fair starting point — but Teams is wired more deeply into the rest of Microsoft 365 than that comparison suggests.

What Teams combines

At its core, Teams gives you:

• Chat — one-to-one and group messages, with threads, reactions, mentions, and persistent history.
• Teams and channels — a team is a group of people; channels are topic-based spaces inside it where conversations and files stay together. Private and shared channels are also supported.
• Meetings and calls — scheduled or instant video meetings, screen sharing, recordings, and transcription. With a Teams Phone licence, Teams becomes a full PBX with external phone numbers.
• Files — every team gets a SharePoint site behind the scenes; the files you drop into a channel live there.
• Apps and tabs — pinned access to Planner, OneNote, Power BI, Loop components, third-party apps, and custom tools.

How it fits with the rest of Microsoft 365

Behind every team is a Microsoft 365 Group, which automatically provisions a shared mailbox, a SharePoint site, a OneNote notebook, and a Planner plan. When you open a file in a channel, you're really opening it from SharePoint. When you @mention someone, you're using their Microsoft Entra ID identity. Permissions cascade from there, which is why governing Teams sprawl is really about governing groups and SharePoint.

What replaced what

Teams replaced Skype for Business as Microsoft's communications client; it has also absorbed much of what people previously used Yammer and SharePoint team sites for. It's the surface where Microsoft now ships most new collaboration features — Loop, Copilot integration, Approvals, Shifts, Bookings — so even if you start out using it just for chat, it tends to grow into the daily home screen for a Microsoft 365 user.