Hi

Can any one explain me, what is the main difference between web server and application server?

Gokulnath

I think a web server is a server that provides web services (websites, hosting etc.) to clients and an application server provides applications (for example programs that are actually run in the server, but so that the client uses them). Or that's what the names imply. A server is generally speaking any machine that provides some sort of services to other machines (clients), so a certain kind of server is just a server that provides certain kinds of services. A web server is for example the machine (or rather machines) that keep eBay's sites on the web, and an application server is for example some machine that provides ASP services. The real difference in the machines is probably just the software that is run on them: on a web server there is something like Apache for example, that does the job of serving web stuff, and on an application server there is some other kind (or kinds) of program(s) running that take care of serving the asked programs to users, and try to keep the thing secure.

Surely somebody (or Wikipedia) knows more specifically.

A webserver can handle only HTTP request that is HTML pages. With that also xml and css. It can store static webpages and also handle some of the client side scripts that can run on any browser. Like jscript and vbscirpt. Earlier they were only used because we needed information which was easily availble in a readable and well formatted style. A webserver can store html pages and images and send them to the client from whom the requset is made.

Now as applications grew big needs grew big, app servers came into action, you can now access your bankaccounts , do transactions buy airtickets shop online, search anything and everything that you can think of in GOOGLE. Also you can post a topic and get a reply, get the status online.. so these kind of things are all dynamic in nature. That is some one has to update is regularly. Here comes JAVA and it needs an enviroment to run and different containers. App servers provide that environment to the java appilcation to execute as it handles the various connection created with the databases using the various connection pools. Apart from that it can run various kinds of java applications as instances which can appept the request from the client and send them back the data after all the computation and calculation in a readable format that is HTML.

So if you look to a java application and a static website its no difference both are accessed by hitting a URL, but internally the reuqest is first forwarded to the HTTP listener (WEB SERVER) and then it is forwared to the APPLICATION SERVER for all the processing that is fetching the data from the database, connnecting to a remote MAinframe server to get some data etc.. and then return the output to the WEB server as HTML which is sent back to the clinet as HTTP (html) pages.

Hope this helps your understanding

Regards