• Implicit objects in jsp are the objects that are created by the container automatically and the container makes all these 9 implicit objects to the developer.
• We do not need to create them explicitly, since these objects are created and automatically by container and are accessed using standard variables(objects) are called implicit objects.
• The following are of implicit variables available in the JSP. 

     1.out
     2.request
     3.response
     4.config
     5.aplication
     6.session
     7.pagecontext
     8.page
     9.exception

1.out:

•  out is one the implicit object to write the data to the buffer and send output to the client in response.
• out object allows us to access the servlets output stream and has a pagescope.
• out.print("");
• out is the object of javax.servlet.jsp.JspWriter class.
• While working with servlet we need printWriter object
• PrintWriter out=response.getWriter();   
• In servlet we are used PrintWriter to send the output to the client. In JSP we use JSPWriter. 
  

Difference between JspWriter and PrintWriter:

• Every JSPWriter is associated with 8KB of internal Buffer. Where as PrintWriter doesn’t associated with any Buffer.
• The methods of the JspWriter class are designed to throw java.io.IOException where as the methods of PrintWriter class are not throw Exception.
• JspWriter is an abstract class present in javax.servlet package.
• PrintWriter is a class defined in java.io package.

JspWriter out object in jsp:

Printwriter object in servlet:

2.request:

• request implicit object is the object of  type  HttpServletRequest.
• request object will be created by the container for every request.
• It will be used to get request information like parameter , header information ,server name server port etc.
• By using request object we can able to set ,get and remove attributes from request scope.
• It uses the getPareameter() method to access request parameter.
• The container passes this object to the _jspService() method.

3.response:

• response is an instance of class which implements the HttpServletResponse interface.
• Container generates this object and passes to the _jspService() method as parameter.
• response object will be created by the container for each request.
• It represents the response that to be given to the client. 
• The response implicit object is  used to content type, add cookie and redirect the response to another resource.

1.set content type.

2.Redirect response:

3. To send the error message directly to the client:

4.config

• config is one of the implicit object of type javax.servlet.ServletConfig.
• config object is created by the web container for each jsp page.
• config object used to get initialization parameters from web.xml file.

• servletConfig is an object used by servlet container to pass the information during initialization.
• Once if we get the ServletConfig object, we can find the name of the servlet which is configured in web.xml file by using a method getServletName() method.

5.application:

• application is one of the implicit object of type javax.servlet.ServletContext.
• application object is created by the web container one per application when the application gets deployed.
• application object used to get context parameters from web.xml file.