Microsoft ASP.NET is a set of technologies, built on top of the Microsoft .NET Framework, for building Web applications and XML Web services. ASP.NET web pages execute on a web server in IIS (Internet Information Server) and generate markup such as HTML, CSS, JavaScript and XML that is sent down to a desktop or mobile device browser. This is important because the application does not require any installation on the client computer beyond a web browser. This means your application can be run from anywhere, anytime, regardless of the hardware.