Microsoft Graph provides a unified API for accessing data across multiple Microsoft services like Azure AD, Exchange, OneDrive, SharePoint, and more. It allows developers to access this data through a single endpoint and uses a common set of HTTP methods, request patterns, and properties. This provides a more streamlined development experience compared to accessing each service individually. The presentation demonstrates how to use the Graph Explorer tool to interact with and explore the Microsoft Graph API. Resources like sample code and documentation are available on the Microsoft Graph website.