Internet Information Services (IIS) provides a secure, easy-to-manage, modular and extensible platform for reliably hosting websites, services and applications. With IIS, you get choice and control without giving up reliability or security.
Windows Server AppFabric extends Windows Server to provide enhanced hosting, management, and caching capabilities for Web applications and middle-tier services. The AppFabric hosting features add service management extensions to Internet Information Services (IIS), Windows Process Activation Service (WAS), and the .NET Framework 4. This includes Hosting Services and Hosting Administration tools that make it easier to deploy, configure, and manage Windows Communication Foundation (WCF) and Windows Workflow Foundation (WF) based services. The AppFabric caching features add a distributed, in-memory object cache to Windows Server that makes it easier to scale out high-performance .NET applications, especially ASP.NET applications.