How does Microsoft 365 Copilot work? (original) (raw)

When you create a Microsoft 365 subscription, you automatically create a tenant for your organization. Your tenant sits inside the Microsoft 365 service boundary, where Microsoft 365 Copilot can access your organization's data.

Operating inside the Microsoft 365 service boundary doesn't grant Copilot tenant-wide visibility. Data access is always scoped to the signed-in user's permissions.

This data includes information that the user can access, including their activities, and the content they create and interact with in Microsoft 365 apps.

Diagram that shows the Microsoft 365 tenant architecture with Microsoft 365 Copilot and user data.

Copilot is a shared service, just like many other services in Microsoft 365. When you use Copilot in your tenant:

This article describes how Microsoft 365 Copilot works, including the data flow in a user prompt, how Copilot accesses data, and how Copilot honors Conditional Access and multifactor authentication (MFA).

This article is intended for IT admins, security teams, and technical decision-makers who want to understand the core architecture of Microsoft 365 Copilot. It focuses on data flow, permissions, and security boundaries.

This article applies to:

User prompts and Copilot responses

When users open a Microsoft 365 app, like Word or PowerPoint, they can use Copilot to get real-time data.

The following diagram provides a visual representation of how a Copilot prompt works.

Diagram that shows the relationship between users, devices, apps, and Microsoft 365 Copilot.

Let's take a look:

  1. In a Microsoft 365 app, a user enters a prompt in Copilot.
  2. Copilot preprocesses the input prompt by using grounding and accesses Microsoft Graph in the user's tenant.

The following video provides an overview of how grounding works in Microsoft 365 Copilot. It's 1 minute and 29 seconds long.

  1. Copilot sends the grounded prompt to the LLM. The LLM uses the prompt to generate a response that is contextually relevant to the user's task.
  2. Copilot returns the response to the app and the user.

User access and data privacy

Copilot only accesses data that an individual user is authorized to access, based on, for example, existing Microsoft 365 role-based access controls. Copilot doesn't access data that the user doesn't have permission to access.

The following diagram provides a visual representation of how Copilot and user access work together.

Diagram that shows Microsoft 365 Copilot only accesses the data the user has permissions to access.

Let's take a look:

To learn more, see Data stored about user interactions with Microsoft 365 Copilot.

Copilot honors Conditional Access and MFA

Copilot honors Conditional Access policies and multifactor authentication (MFA).

Diagram that shows Conditional Access and MFA can control access to Microsoft 365 Copilot.

This means: