Forward():By using forward() method of RequestDispatcher ,ew
can forward a request to a another resource(i.e
servlets,jsp,html....),at finally we can see only called
resource output(i.e second resource output )
For exm. we have two servlets,(servlet1 and servlet2) we are
forwarding request from servlet1 to servlet2, in this case
we can see only servlet2 output.
include():By using include() method of RequestDispatcher we
can forward a request from servlet12 to servlet2 ,in this
case we can see  both outputs(i.e servlet1 and servlet2).

in both case single request and single response.

forward() is used to just forward the request and response
object...

include() is used to pass the values and request and
response object,one servlet to another servlet

Forward():

In ServletRequestDispatcher ,By using forward() method,we 
can forward a request to a another resource(i.e
servlets,jsp,html....),at finally we can see only called
resource output(i.e second resource output,i.e response)
For exm. we have two servlets,(servlet1 and servlet2) we are
forwarding request from servlet1 to servlet2, in this case
we can see only servlet2 output(i.e response for the 
request).
in forward()it will take only servlet1 output.
(ex: in servlet we a\are having some name like srinu with 
background color blue, it will take only the name not the 
color)

include():

By using include() method of RequestDispatcher we
can forward a request from servlet1 to servlet2 ,in this
case we can see  both outputs(i.e servlet1 and servlet2).

in include()it will include the servlet1 page and 
forwarding to the servlet2)
in this  case we can see both servlet1& servlet2 as the 
part of response.

forward will make the flow into a different page,where as
include mechanism will include the page to the current
response and continues the flow.
Note:the forward and include should be called before the
response is committed for example before the call to flush()
or flushBuffer() or the write method in the response stream

forward will make the flow into a different page,where as
include mechanism will include the page to the current
response and continues the flow.
Note:the forward and include should be called before the
response is committed for example before the call to flush()
or flushBuffer() or the write method in the response stream