A: If deciding on an Office 365 plan, you also need to consider how your organization's end users are going to access their new SaaS offering. Identity management and authentication is a comprehensive topic whose nuances are outside the scope of this handbook, but the following general information will help you get started. For SharePoint Online, Microsoft basically offers three different types of authentication mechanisms:
Microsoft Online Services IDs
Microsoft Windows Live IDs
ADFS 2.0 and Single Sign On (SSO)
Note
Microsoft also has a product called Forefront Identity Manager 2010, which can be integrated for managing identities, credentials, and identity-based access policies. For more information, refer to http://www.microsoft.com/en-us/server-cloud/forefront/identity-manager-overview.aspx.