Introduction to ASP
ASP stands for Active Server Pages. It was launched by Microsoft in 1996. It runs under IIS (Internet Information Server), which comes free with Windows 2000 / NT4.0 Option Pack, and PWS, which comes with Windows 95/ 98. You may need to download or install them from disk (for details see W3Schools).
An ASP file (*.asp) an contain text, HTML, XML, and scripts. When your browser requests an ASP file IIS passes the request to the ASP engine (ASP.DLL) on the server. This reads the file and produces HTML which is sent to the browser - any browser can read it. The user never gets to see anything but the HTML. This allows pages to be generated on request, perhaps customised, and for the code to be protected from users.