You can see the following illustration to better understand the lifecycle of the
Servlet.
When the request of users to Servlet, the servlet will call the method of
service() to serve the requirements of users, the
service() will call either
doGet() or
doPost().
The figure below illustrates how
WebContainer decided to use
Servlet to service request from the client.
https://o7planning.org/en/10169/java-servlet-tutorial
This section explains how to handle the errors notified to Servlet Container.
