Facebook Inc. operates a social networking website worldwide. The Company's products for users are free of charge and available on the Web, mobile Web, and mobile platforms, such as Android and iOS. Its website enables users to connect, share, discover, and communicate with each other. The Facebook Platform is a set of tools and application programming interfaces that developers can use to build social apps on Facebook or to integrate their Websites with Facebook. It offers products that enable advertisers and marketers to engage with its users. Facebook Inc. is headquartered in Menlo Park, California.