What is Microsoft Copilot?

Microsoft Copilot is an AI-powered assistant built directly into the Microsoft 365 suite of applications. It is not a separate application you need to download or a website you need to visit — it is embedded within the Word, Outlook, Teams, SharePoint, and Excel applications you already use every day. When you open a document in Word and see the Copilot icon in the toolbar, or when you compose an email in Outlook and see the option to draft with Copilot, you are interacting with the same underlying AI technology that is transforming how legal professionals work.

The Technology Behind Copilot

Microsoft Copilot is powered by large language models (LLMs), specifically the GPT-5.2 model developed by OpenAI in partnership with Microsoft. Large language models are AI systems trained on enormous amounts of text data — books, articles, websites, code, and other written material — that learn to understand and generate human language with remarkable fluency and contextual awareness.

When you type a prompt into Copilot — for example, “Summarize this deposition transcript focusing on the witness’s testimony about the timeline of events” — the LLM processes your instruction along with the content of the document and generates a response that attempts to fulfill your request. The model does not simply search for keywords or retrieve pre-written summaries; it generates new text based on its understanding of both your instruction and the document content.

What makes Microsoft Copilot particularly powerful for legal professionals is the way it integrates with Microsoft Graph — the underlying data layer that connects all of your Microsoft 365 content. Microsoft Graph allows Copilot to access your emails, documents, calendar, Teams conversations, and SharePoint files (subject to your existing permissions) and use that context to generate more relevant, grounded responses. When you ask Copilot to draft a client update email, it can draw on your previous correspondence with that client, the relevant documents in your matter folder, and your calendar to produce a draft that is contextually appropriate and accurate.

Copilot Work vs. Copilot Web: A Critical Distinction

One of the most important concepts in this course is the distinction between Copilot Work and Copilot Web. Understanding this distinction is essential for maintaining client confidentiality and meeting your professional responsibility obligations.

Copilot Work is the enterprise version of Copilot that operates entirely within your firm’s secure Microsoft 365 tenant. When you use Copilot Work, your prompts and the documents you reference are processed within Microsoft’s enterprise infrastructure, subject to your firm’s security policies and compliance controls. Your data is not used to train Microsoft’s AI models, it is not accessible to other organizations, and it does not leave your controlled environment. This is the version of Copilot you should use for all client matters, privileged communications, and any work involving confidential information.

Copilot Web (also accessible through Microsoft Edge and Bing) is the consumer-facing version of Copilot that connects to the public internet and uses Bing search to ground its responses. While Copilot Web has enterprise protections when accessed through a Microsoft 365 account, it is designed for general research and information gathering rather than for processing confidential client information. You can use Copilot Web for tasks like researching publicly available legal developments, drafting generic content that does not involve client information, or learning about new legal topics. You should never use Copilot Web to process client names, case facts, privileged communications, or any other confidential information.

The 2026 Feature Landscape

Microsoft releases new Copilot features on a monthly basis, and the capabilities available in 2026 represent a significant advancement over the initial release. Several features introduced in late 2025 and early 2026 are particularly relevant for legal professionals:

Agent Mode is a new capability that allows Copilot to actively edit and refine documents while showing its reasoning process in real time. Rather than generating a single response and waiting for your next prompt, Agent Mode allows Copilot to work through a multi-step task — for example, reviewing a contract, identifying issues, drafting suggested revisions, and creating a summary memo — with transparency about each step it is taking. This is particularly valuable for complex document review tasks.

Advanced Voice Interaction allows you to interact with Copilot using natural speech, including on mobile devices. For attorneys who spend time commuting or traveling, this means you can use your morning drive to catch up on overnight emails, dictate responses, and organize your day — all hands-free. The voice feature includes speaker identification in Teams meetings, allowing Copilot to attribute meeting notes and action items to specific participants.

Local File Support extends Copilot’s reach beyond cloud-stored documents to include files stored locally on your computer. This is important for attorneys who work with documents that have not yet been uploaded to SharePoint or OneDrive, ensuring that Copilot can assist with the full range of your document library.

Python in Excel allows you to use natural language to perform complex data analysis in Excel, including generating visualizations and running statistical models. For attorneys who work with financial data, billing records, or case management spreadsheets, this feature dramatically reduces the technical barrier to sophisticated data analysis.

How Copilot Fits Into Your Existing Workflow

One of the most important things to understand about Microsoft Copilot is that it is designed to fit into your existing workflows rather than requiring you to adopt entirely new processes. You do not need to learn a new application, change your document management system, or restructure how your firm operates. Copilot is available wherever you already work — in Word when you are drafting, in Outlook when you are managing email, in Teams when you are in a meeting, in SharePoint when you are organizing documents, and in Excel when you are analyzing data.

The learning curve for Copilot is primarily about developing effective prompting skills — learning how to communicate with the AI in a way that produces the results you need. This is a skill that improves with practice, and the next section of this course is dedicated entirely to teaching you the five-element framework for writing prompts that consistently deliver high-quality, relevant results.