Introduction

Identity is how people, devices, and applications prove who or what they are when accessing digital resources. In a world where work happens from anywhere and data spans cloud and on-premises systems, identity has become the central security control organizations rely on.

This module introduces the foundational identity concepts that underpin the Microsoft security, compliance, and identity portfolio. It starts with authentication and authorization—the processes of proving identity and determining access. From there, it explores why identity has replaced the network perimeter as the primary security boundary, and why this matters for every organization. It covers how identity providers enable modern, centralized authentication and single sign-on, then looks at how directory services—from traditional Active Directory to cloud-based Microsoft Entra ID—store and manage identity information at scale. Finally, it covers how federation extends trust across organizational boundaries so users can access resources in different domains without separate accounts.

After completing this module, you'll be able to:

• Define authentication and authorization and explain how they work together to control access.
• Describe identity as the primary security perimeter and explain the four pillars of an identity infrastructure.
• Describe the role of an identity provider and how modern authentication uses tokens and single sign-on.
• Describe directory services, Active Directory Domain Services, and Microsoft Entra ID as its cloud evolution.
• Describe the concept of federation and how trust relationships enable cross-organizational access.