A web application is application software that runs on a web server, unlike computer-based software that runs locally on the operating system (OS) of the device. Web applications are accessed by the user through a web browser with an active network connection. These applications are programmed using a client-server-style architecture - the user (the "client") is provided by an off-site server hosted by a third party. Examples of commonly used web applications include: email, online retail sales, online banking, and online auctions.