Copilot is Microsoft's AI brand, woven through the tools much of the corporate world already lives in: Word, Excel, PowerPoint, Outlook, Teams and Windows itself. It drafts documents, summarises meetings, writes formulas and answers questions, powered largely by OpenAI models through Microsoft's partnership, plus Microsoft's own.
Its superpower is placement, not quality. Like Gemini in Google Workspace, Copilot arrives pre-installed, IT-approved and connected to your company's documents and email, which is exactly what makes it the default AI in large organisations.
The word also has a generic life: GitHub Copilot was the original AI coding assistant, and "a copilot for X" became startup-speak for any assist-style AI product.
Why you keep hearing it
Because Microsoft put an AI button in front of hundreds of millions of office workers. For a large share of them, Copilot is their entire experience of AI, and their opinion of it becomes their opinion of AI in general.
What it means for you
If you work somewhere on Microsoft 365, Copilot is probably your sanctioned option, and it is genuinely useful for meeting summaries and document drafts. Just do not let it be your only reference point: the frontier assistants (Claude, ChatGPT) show you what AI can actually do.