Servlets are Java objects that implement the Java Servlet API originally defined by Sun for dynamic web page creation.
Servlets process ServletRequests and generate ServeletResponses to service http requests, these servelets are contained by servlet containers such as Tomcat or Jetty, which map URLs to servlets.
Today the servlet specification is managed by the Java Community Process, under the specification JSR-154.
In Java World Servlets are popularly used for Model View Controller (MVC) Design Pattern. This article will guide you on writing AJAX based application for fetching data from the Servlet and showing it on JSP page. To read this article check this link: Ajax Programming With JSP and Servlets
Servlet
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jsp,