What's inside
AB-900 doesn't test menu names. It tests whether you know which admin center, role, Purview control or Copilot setting fits a need, and what each one does not do.
This independent study guide for the Microsoft 365 Certified: Copilot and Agent Administration Fundamentals exam distils what AB-900 really expects you to understand into clear explanations, comparisons and the traps that catch beginners. It uses Microsoft's current names, including Microsoft Copilot (formerly Microsoft 365 Copilot), and notes where older material and today's product differ.
Organised by technology
Nine chapters, each readable on its own and together covering all three AB-900 skill areas:
- Microsoft 365 services: tenants, licences and group-based licensing, domains and org settings in the Microsoft 365 admin center, mailboxes and groups in Exchange Online, SharePoint sites, libraries and permissions, and Teams channels and policies.
- Identity and security: Zero Trust, authentication methods and number matching, Microsoft Defender XDR, Microsoft Entra ID, Conditional Access, single sign-on, sign-in troubleshooting, Identity Secure Score, audit logs, Global Reader and Privileged Identity Management.
- Data protection and Copilot: sensitivity labels, data classification, DLP and retention in Microsoft Purview; how Copilot reaches data through Microsoft Graph and web search; Compliance Manager, Data explorer, Insider Risk Management, Communication Compliance, DSPM for AI and Content search; and SharePoint oversharing controls from data access governance reports to restricted access control and Restricted Content Discovery.
- Copilot and agents: the per-user licence versus pay-as-you-go billing policies and Copilot Credits, the Copilot settings you can turn on and off, Researcher and Analyst, Agent Builder, agent access and approval, and monitoring usage in the Microsoft 365 admin center and Power Platform admin center.
Inside
- Comparison tables for every close call, such as which group type, which oversharing control or which report fits a requirement.
- 80+ Common trap callouts that name the answers that look right but aren't, and explain what's right instead.
- 11 diagrams, from licence assignment and Conditional Access to the Copilot prompt flow and the agent approval process.
- Key takeaways at the end of every chapter for fast revision.
- A glossary of 270+ terms, each linked to Microsoft Learn, with a free online version for print readers.
Up to date
Microsoft 365 and Copilot change quickly. This edition reflects Microsoft's documentation as of October 2026, including the Copilot renaming, the new Copilot admin pages and recent retirements.
Understanding, not memorising
This book contains no exam questions. It explains the knowledge the exam expects, so you can answer questions you have never seen and administer Copilot and agents with confidence at work.
Written by Tony Rough, a cloud architect with more than twenty years in IT infrastructure who holds the Azure Solutions Architect Expert, Azure Administrator and Azure Security Engineer certifications.
Part of the Ultra Transcenders series from Distilled Press. An independent publication, not affiliated with, sponsored by or endorsed by Microsoft Corporation.
