Active Server Pages (ASP) is a server-side web application framework that enables the creation of dynamic, interactive websites and applications. It is a specialized skill involving a programming language, usually VBScript or JScript, and database connectivity to develop web applications that can communicate with databases, generate dynamic web pages and provide a user-friendly interface. ASP is primarily used with Microsoft's IIS web server and can be used to build anything from simple websites to complex web-based applications.