1. App Fabric:

   App Fabric is a set of middleware technology for windows server released by Microsoft. It consists of two main feature areas.

   a. App Fabric Hosting

   b. App Fabric Caching

2. App Fabric hosting: these feature provide an easy way to delay and, mange window workflow foundation (WF) workflows that are hosted in windows communication Foundation (WCF) services.

3. App Fabric Caching: It is an in-memory, distributed cache that runs on one/ more on-premise servers to provide a performance and scalability boost, App Fabric caches stores data in key-value pairs using the physical memory access multiple servers.

   App Fabric Access Control Services:

   a. It offers you a way to outsource authentication and decouple your application from all the complexity of maintain a direct relationship with all identify providers.

   b. ACS takes care of engaging every identity provider with its own authentication protocol, normalizing the results in a protocol supported by .NET framework tooling (WF) regardless of form where user is coming.

   Features of App Fabric ACS:

   a. Acts as authentication manager for client application.

   b. Provides a user interface for the user to choose the reorganized identify provider.

   c. Drive authentication decisions.

   d. Usable from any platform

   e. Enables simple delegation.

   ACS management Portal: the ACS based federated authentication settings are managed under this area of portal.

   Therefore there are two step for the set put- Identity providers and specify relying party apps.

   Steps:

Hence ACS is a security token service that supports claim based authentication and authorization by several methods.

1. Username/password

2. Window Live IO

3. Windows CardSpace

4. X.509 certificate

5. SAML (Security Assertion Markup Language).