Windows Server powers many of the worlds' largest datacentres, enables small businesses around the world, and delivers value to organizations of all sizes in between. Building on this legacy, Windows Server 2012 redefines the category, delivering hundreds of new features and enhancements spanning virtualization, networking, storage, user experience, cloud computing, automation, and more. Simply put, Windows Server 2012 helps you transform your IT operations to reduce costs and deliver a whole new level of business value. A server Client Access License (CAL) is a license that gives users and devices the legal right to access a server installed with Microsoft server software. When you sell a copy of Windows Server, the customer will receive a server license permitting installation of the operating system on one computer. A server license by itself does not provide the legal right for others to connect to that computer, whether they work for the company or not. Instead, each user needs a Client Access License (CAL). Customers will need a CAL for each employee, or each employee device, that accesses the Windows Server, but not for anonymous users who access it over the Internet.