Explanation:

Microsoft 365 Copilot Chat is included at no additional cost for users with qualifying Microsoft 365 subscriptions such as Business Basic, Business Standard, Business Premium, E3, and E5. Therefore, users without a Microsoft 365 Copilot add-on license can still access Copilot Chat.
Copilot Chat allows users to upload documents from their local device within a session for summarization, analysis, and drafting assistance. However, advanced enterprise-integrated features-such as creating agents that access organizational SharePoint folders-require a Microsoft 365 Copilot license.
Agent creation and enterprise data grounding leverage Microsoft Graph integration and are considered premium Copilot capabilities tied to licensed Copilot services.
This distinction reflects Microsoft's licensing model: baseline AI chat access is included with qualifying subscriptions, while deep Microsoft 365 app integration and enterprise data agents require the additional Copilot license.