AB-900 Course Notes

Core Microsoft 365 administration starts with knowing which tenant object solves the request. A distribution group gives users one email address for sending messages to multiple recipients, while a user mailbox belongs to one licensed user and a shared mailbox lets multiple people work from a common address such as support or billing. The Exchange admin center is the correct place for many mailbox and recipient tasks, so exam items often separate mail administration from SharePoint, Teams, or license management.

Microsoft 365 administration starts in the Microsoft 365 admin center, where admins manage users, domains, subscriptions, billing, licenses, groups, and service health. The exam expects you to know when the admin center is the right portal for tenant-wide account and licensing work, and when a workload-specific admin center is needed instead. Service health belongs in this foundation because admins must distinguish a Microsoft service incident from a local configuration or user problem.

Microsoft Purview is the center of gravity for Microsoft 365 compliance, data protection, and governance. Purview solutions help admins classify data, retain or delete content, investigate activity, manage communication risk, detect insider risk, and respond to legal or regulatory obligations. The exam usually asks which Purview capability fits a risk: DLP protects sensitive information in use, retention manages lifecycle, sensitivity labels classify and protect content, and Activity Explorer helps investigate what happened.

SharePoint oversharing questions usually start with Data Access Governance reports. These reports help admins find sites with broad internal access, external sharing, Anyone links, sharing-link activity, and sensitivity-label inconsistencies. The exam distinction is that the report identifies the risk; remediation happens afterward through sharing settings, site access review, restricted access controls, label cleanup, or link removal.

GitHub Copilot modernization is an adjacent AI topic about assessing and upgrading application code, especially Java, .NET, and supported app modernization scenarios. The value is not simply code completion; the modernization agent analyzes an application, identifies dependencies and framework concerns, and recommends a path for bringing older code closer to a cloud-ready or Azure-ready architecture.

Copilot administration starts with knowing which users have access and which billing model applies. License assignment grants Microsoft 365 Copilot capabilities to eligible users, while license removal affects future access to licensed Copilot features. Pay-as-you-go is a separate billing model for supported Copilot services and scenarios, so admins must connect the right billing policy rather than assuming every Copilot feature is controlled only by user licenses.

AI-powered automation questions separate simple prompt agents from more structured workflow or hosted agents. A prompt agent is useful for rapid prototyping or straightforward natural-language assistance driven mainly by instructions and knowledge. A workflow agent is better when the scenario needs branching, orchestration, or a defined sequence of actions. A hosted agent fits code-based or more advanced implementations where runtime behavior and tools need stronger engineering control.