ASP.NET (acronym for Active Server Pages) is Microsoft’s technology for creating dynamic, rich, attractive and scalable web applications that run on server instead on client’s pc. Before ASP.NET, (in the era of CGI standard) web servers had to launch a separate instance of a website for each request. This method, as you can imagine, can generate problems for a famous website that accepts hundreds of requests in a minute. It would definitely generate a lot of load on the web server. To fix this Microsoft created technologies like ASP and ASP.NET. The original ASP technology became very famous, more than Microsoft could imagine. ASP was being used in almost every category of websites. The developers of ASP didn’t design it with that picture in mind, so it started to fall. To correct the mistakes of ASP, ASP.NET was developed as an industry strength web application framework that could address the limitations of ASP.
Note: ASP and ASP.NET despite having the same name (or partially same name) are radically different from each other. You can learn the differences between ASP and ASP.NET via internet. They won’t be covered in this tutorial.
Before server side programming, web developers widely used client side programming to enhance their websites (Client side programming is also used widely today). In client side programming, the developer included embedded applets (a very small application that performs a specific task) that were downloaded on the client’s computer and were executed on client’s pc rather than the server.
One of the major problems in this methodology that it wasn’t supported equally by all browsers or operating systems. So, the developers had to test their web applications in different browsers and operating systems and even had to provide browser updates. Server side programming was a better alternative.
Server Side Programming:
In server side programming, as used in ASP.NET, all the web application code is executed on the server and the client’s browser just receives the HTML document.
This figure explains how server side programming works (Click on it to enlarge):