Hai friendz i am rajendra,

I would like to give simple and easy answer for this 
question,
Error -A Fault in the program leads to error in program  
       exection.
Defect-If the error caught by tester then it  is  called
       as defect.
Bug -  If the defect is accepted by the development people
       then it is called as Bug.

          Fault---->Error---->Defect---->Bug
Error may be generated due to  syntax or symantic fault.

Different types of error are 
         1.syntax errors
         2.symantic errors
         3.Logical errors
         4.Runtime errors...etc

All athe above errors will be occured during white box 
testing of the application/product.

In BlackBox testing main defects are
         Requirement missing or
         Wrongly interpreted requiremets,
         Misoperation of fuctionalities...etc.

ok byeeee
 rajendra_penumalli@yahoo.com
09885162742
hyderabad