Difference between web server and application server?

A Web server serves pages for viewing in a Web browser, while an application server provides methods that client applications can call.

The Web server

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. To process a request, a Web server may respond with a static HTML page or image, send a redirect, or delegate the dynamic response generation to some other program such as CGI scripts, JSPs (JavaServer Pages), servlets, ASPs (Active Server Pages), server-side JavaScripts, or some other server-side technology. Whatever their purpose, such server-side programs generate a response, most often in HTML, for viewing in a Web browser.

The application server

As for the application server, according to our definition, an application server exposes business logic to client applications through various protocols, possibly including HTTP. While a Web server mainly deals with sending HTML for display in a Web browser, an application server provides access to business logic for use by client application programs. The application program can use this logic just as it would call a method on an object (or a function in the procedural world).

Webserver is used only for jsp and servlets and for static functionality it has limited functionality and it doesn’t provide any security persistence and it doesn’t support EJB and JMS and JAAS like other functionality

whereas Application server provide all functionalities

In simple words, Application Server = Web Server + EJB Container