WebServer and ApplicationServer

WEB SERVER:
Web servers are computers on the Internet that host websites, serving pages to viewers upon request.
A Web server handles the HTTP protocol. When the Web server receives an HTTP request it responds with an HTTP response such as sending back an HTML page.
Webserver is designed for Website deployments and web based apps.

APPLICATION SERVER:
Application server is a server that provides XML web Services, WEb Applications and distributed apps.
An application Server exposes business logic to client applications through various protocols possibly including HTTP.
Application Server is used to Deploy an Application and then that application can be accessed using webserver.

The difference between WebServer and ApplicationServer is
1. Web Server serves static HTML pages or gifs, jpegs, etc.,
An Application Server is used to run business logic or dynamically generated presentation code.
2. A Web Server understands and supports only HTTP protocol, an Application Server supports HTTP,TCP/IP and many more protocols.
3. Application Server will take care of all these issues like Security Transaction Multithreading Resource pooling etc...
In Web Server it is not possible...