Active server pages (also commonly referred to as classic ASP) is a technology developed by Microsoft that enables web developers and programmers to generate interactive web pages with dynamic content. Apart from containing the HTML code and text, these webpages contain server-side scripts which are executed on the Web hosting server before the page is returned to the user's browser. This results in a page that is custom tailored to the requirements of the user because of the specific input taken. In the beginning, ASP was provided as an add-on to Internet information services which was bundled with the Windows NT operating system. Later, Windows server also utilized the ASP technology as a free component. Presently, ASP has been replaced by ASP.net.

Active server pages cannot be run by loading conventionally into a web browser. There must be a Web hosting server capable of supporting ASP through which the page is processed and returned in order for the functionality in it to function. This is the reason why they are named "active server pages" because they cannot work without a supported hosting server. Instead of the normal.html extension, active server pages have an extension of.asp which results in their immediate recognition by the Web hosting server. Any scripts residing within the page are consequently processed and the page together with the HTML in it is returned to the browser.

To the user, an ASP page looks no different from a normal HTML page. Even if the user peeps into the source code of the page, it will only have the HTML code in it. However the code contained within the page residing on the web hosting server is quite different from the HTML code that the user is able to see. It contains multiple server-side scripts which only the Web hosting server is able to see. The scripts contained within the ASP page can be used to perform a variety of functions ranging from displaying the current date and time to using it in a survey form as well as sending e-mail. All the top web hosting companies listed at AWHD support the ASP technology.