ASP (Active Server Pages) was for the first time was released in December 1996. Since then it has been through major changes and has grown and tailored to the new methods of developing web sites and applications for the internet over the period of time. There are two major forms of ASP:
o Classic ASP and
In ASP classic the executable code can not be separated from the HTML making the page difficult to read and maintain. The code block has to be placed when ever the output is to be shown. This limitation of code is overcome in ASP.net by the use of server controls. The HTML and Web Server Controls created on the server require a attribute to work. This attribute indicates that the page will be processed on the server. At the same time it implies that the enclosed controls can be accessed by server scripts. Validation Server Controls are a big advantage in ASP.net. It saves a lot of time and developers do not have to write their own functions as it is with ASP. Built-in validation increases the application reliability. Through this Double validation on client and server side can be performed.