ASP stands for Active Server Pages. It is a Microsoft Technology. ASP is a program that runs inside Internet Information Services. To run IIS, we need Windows NT or later. PWS is a smaller, but fully functional version of IIS. To run PWS, we need Windows 95 or later. InstantASP, ChiliASP are technologies that run ASP without Windows Operating System.

An ASP file has the file extension of ‘.asp’. An ASP file can contain text, HTML, XML and Scripts. Scripts in an ASP file are executed on the server.

Difference between ASP and HTML

When a browser requests an ASP file, IIS passes the request to the ASP engine. The ASP engine reads the ASP file, line by line, and executes the scripts in the file. Finally the ASP file is returned to the browser as plain HTML. But for HTML file, server returns the file.

Functions of ASP

Dynamically edit, change or add any content of a web page.
Access any database and return the results to the browser.
Respond to user queries submitted from HTML forms.
Customize a web page to make it more useful for individual users.

Advantages of ASP

Simplicity and speed compare the CGI and Perl
Provided security since ASP code cannot be viewed from the browser.
ASP pages can be viewed in any browser, because ASP files are returned as plain HTML.
Minimize the network traffic.

A group of ASP files that work together to perform some purpose is called an application. The Application object in ASP is used to tie these files together. An application on the Web may be a group of ASP files. The ASP files work together to perform some purpose. The Application object in ASP is used to tie these files together.
The Application object is used to store and access variables from any page, just like the Session object. The difference is that ALL users share one Application object, while with Sessions there is one Session object for EACH user.
The Application object should hold information that will be used by many pages in the application (like database connection information). This means that you can access the information from any page. It also means that you can change the information in one place and the changes will automatically be reflected on all pages.