When organizations subscribe to Microsoft Online Services, they purchase licenses for their users. When a users leave the organization and new people join, administrators’ve several options for accommodating these personnel changes, including: “Disabling a user account prevents user access to e-mail and Microsoft SharePoint Online data, but retains the user’s data, and also keeps the user license associated with that account. Or Deleting a user account frees the user license, allowing the license to be assigned to a different user, and permanently delete all information associated with the user's account: for example, the user's profile data and e-mail messages. Or, if an organization is growing and needs additional user licenses, additional licenses can be purchased at the Microsoft Online Services Customer Portal or through a Microsoft Online Services partner.”