ASP Full Form is Active Server page. This is a HTML page, which includes scripts on a Microsoft Web server before it is presented to the user. It is similar to a CGI or Common Gateway Interface application. It is also termed as Classic ASP. It is the first every server-side script engine of Microsoft. This is exclusive for dynamic web pages. ASP.NET was first released in the year 2002.
ASP is a part of Microsoft Internet Information Server or IIS. However, since the script on server side is building a HTML page, it can be given out to any browser. In simple terms, ASP file is same as the HTML file. It has an extension ‘.asp’. Nevertheless, the basic difference between HTML and ASP are; (1). When browsers request HTML files, they are returned by the server (2). When browsers request ASP file, a request is passed to the ASP engine by the IIS. The ASP engine then reads every line of the ASP file and executes them. Finally, the ASP file is returned in the form of plain HTML to the browser.