||Defines an object that receives requests from the client
and sends them to any resource (such as a servlet,
HTML file, or JSP file) on the server.
||Defines methods that all servlets must implement.
||Defines a servlet configuration object, which a servlet engine
uses to pass information
to a servlet in order to initialize the servlet.
||Defines a set of methods that a servlet uses to communicate
with a servlet engine, for example, to get the MIME type of a file,
locate other servlets running on the server, or
write to a servlet log file.
||Defines an object that a servlet engine uses to give
a servlet information about a client request.
||Sends MIME-encoded data from the servlet to the client.
||Ensures that servlets handle
only one request at a time.