Adhoc testing:
              If there is no proper testplan at that time 
we can perform adhoc testing.It has some sample test cases.

Exploratory testing:
                    If there is no test plan we can study 
the SRS (Requirements documents) at that time,and 
simulteneously we can perform testing.This is commonly 
called as exploratory testing

Muralidharan

dharanmu@yahoo.com