Microsoft Copilot is the AI layer woven into Windows 11, Edge, and the entire Microsoft 365 suite. It can summarize your emails, draft documents in Word, generate formulas in Excel, and build presentations in PowerPoint - without leaving the apps you already live in. At its core it runs on GPT-4o, with Bing's live web index giving it access to current information. The free version is available to anyone with a Microsoft account; Copilot Pro adds deeper integration with Office apps and faster response times for $20/mo. For enterprises already standardized on Microsoft's stack, this is often the path of least resistance to AI-assisted work. It doesn't do everything better than standalone tools, but it does it where you already are.