Web server only supports Web application like Servlets, JSP, HTML and Application Server support Enterprise Edition like Servlets , JSP , HTML, EJB (Enterprise Java Bean) , JMS (Java Message Service) and the Application Server is Superior (Web Server + EJB + JMS).
An application server opens business logic to browser applications through various protocols, potentially including HTTP. While a Web server chiefly manages sending HTML for expose in a Web program, an application server gives access to business logic to utilize by browser application programs.
javax.servlet.* package contains a number of classes and interfaces that define the agreement between the servlet class and the run-time environment provided an instance of the servlet class by a conforming servlet container.
javax.servlet.http.* package contains a number of classes and interfaces that define the agreement between the servlet class under HTTP protocol and the run-time environment provided an instance of the servlet class by conforming servlet container.
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