Microsoft 365 Copilot Fundamentals

If your company has switched on Microsoft 365 Copilot, you now have an AI assistant sitting quietly inside the apps you already use every day. It is not a separate website you log into and copy-paste between. It is built into Word, Excel, PowerPoint, Outlook and Teams, and it also has its own chat space called Microsoft 365 Copilot Chat. Understanding what it can see, where it lives, and how to talk to it is the difference between a gimmick and a genuine time-saver.

Where Copilot shows up

There are really two ways you meet Copilot. The first is Copilot in the apps — the assistant pane that appears inside a specific document. In Word it drafts and rewrites; in Excel it analyses your table; in PowerPoint it builds slides from a document; in Outlook it summarises a long email thread and drafts a reply; in Teams it recaps a meeting you missed. It works on the thing in front of you.

The second is Copilot Chat, a standalone conversation you can open in Teams, in the Microsoft 365 app, or in a browser. Here you ask questions that span your whole work world: “Summarise everything I missed from the Henderson account this week,” or “Find the latest version of the onboarding deck and tell me what changed.” Same assistant, wider view.

Grounded in your data — and only your data

The thing that makes Copilot more than a chatbot is grounding. Copilot is connected to your organisation’s data through the Microsoft Graph — the index that already knows about your emails, files, chats, meetings and the people you work with. When you ask a question, Copilot pulls relevant material from that graph and uses it to answer, so its replies are about your projects, not generic internet trivia.

Crucially, Copilot respects your existing permissions. It can only see what you can already see. If you do not have access to the finance team’s folder, Copilot cannot read it for you either. It does not widen your reach; it just makes the access you already have faster to use. Your data also stays inside your organisation’s compliance boundary — it is not used to train the public model.

Work vs. web

Inside Copilot Chat you will see a small but important toggle: work versus web. In work mode, Copilot grounds its answer in your organisation’s data — your files, emails and chats. In web mode, it answers from public internet knowledge, like a general AI assistant, and does not touch your internal material. Pick the right one for the job. Asking “what’s the standard maternity-leave policy in our handbook?” needs work; asking “what’s a common framework for SWOT analysis?” is fine on web.

Writing prompts Copilot can actually use

Copilot is only as good as the request you give it. Vague in, vague out. The habit that helps most is to add context, a goal, and a format. Instead of “write something about the project,” try “Draft a three-paragraph status update for the Henderson rollout for a non-technical client, friendly but professional.” Tell it who it is for, what you want, and how long or what shape the answer should take. Point it at a specific file or email thread when you can. And do not be afraid to follow up — “make it shorter,” “add a risk section,” “use bullet points” — because Copilot remembers the conversation.

Rule of thumb: treat Copilot like a capable new colleague — give it context and a clear brief, then check its work before you put your name on it.

Spot it: Work vs. Web mode

Read each situation and decide for yourself, then tap a card to flip it and check your answer.

Sort the Copilot approaches

Drag each task into the bucket it belongs to — or tap an item, then tap a bucket. Hit Check placement when you’re done.

Always verify

Here is the rule you must never drop. Copilot is fast, fluent and confident — and sometimes confidently wrong. It can misread a document, blend two sources, or invent a detail that sounds plausible. So read what it produces before you trust it. Check the figures, click the citations it offers, and ask yourself whether the answer matches what you actually know. Never paste confidential data into AI tools your company has not approved, and never forward a Copilot draft to a client without reading it first. Copilot does the heavy lifting; you stay accountable for the result.

How to use it

Start small and build the habit. In Outlook, ask Copilot to summarise a long thread before you reply. In Teams, get a recap of a meeting you missed. In Word, ask it to draft a first version you then refine. In Copilot Chat, switch to work mode and ask it to pull together everything on a project. When you prompt, name the audience, the goal and the format. Useful phrases: “Copilot, summarise this thread and list any action items for me.” “Switch to work mode and find the latest version of that file.” “Good first draft — now make it shorter and add a risks section.” “Let me verify those numbers before I send this.” That last one keeps you on the right side of using AI well.