Until now, a user would typically be assigned to an admin role through the Azure portal, some other Microsoft Online Service portal, or through Azure AD PowerShell cmdlets. Doing so would make the user a permanent administrator, which in turn meant that the user was always active in the assigned admin role. With Azure AD Privileged Identity Management comes the idea of the Eligible admin. An Eligible admin is a user that needs some sort of privileged or admin-level access every now and again, but not all the time. In this scenario, the privileged role is inactive until the user needs the privileged access that it provides. The user then completes an activation process to become an admin for a preconfigured time frame. Many organizations prefer the strategy of granting admin access because it reduces or even eliminates permanent admin access to privileged roles. Some key terms to understand are eligible role user and delegated approver. An eligible role user is a user that's been assigned as eligible to an Azure AD role. This requires the role to be activated when needed. 

A delegated approver is a user, or maybe even multiple users or groups, within Azure AD who is responsible for approving requests to activate such roles. An example of these roles in action would be a case where John is designated as a privileged role administrator. In such a case, John would have the ability to enable approval for specific roles, and he could also specify approver users and groups to approve requests. John would also be able to view the request and approval history for all privileged roles. In another scenario, Jen might be a designated approver. As a designated approver, Jen would be able to view pending requests and approvals, and she would also be able to approve and reject role elevation requests. She would also be responsible for providing justification for approvals and rejections. An example of an eligible role user would be Dave. As an eligible role user, Dave would be able to request activation of a role that requires approval. After the role activation is approved by Jen, he would then be able to complete his tasks in Azure AD. As you can probably tell by now, Privileged Identity Management offers streamlined, yet granular management scenario support.