When a user clicks a Submit button, information entered in a display page is sent to a servlet. The servlet processes the incoming data and orchestrates a response by generating content. Once the content is generated, the servlet creates a response page, usually by forwarding the content to a JSP. The response is sent back to the client, which sets up the next user interaction.
The following illustration shows the information flow to and from the servlet.
 To show the servlet data flow
To show the servlet data flow