fuctionality, structral

testing the internal interfacing is called white box and
testing the outer interfacing is black box testing

Black box testing: Using specifications to come up with test
cases.
White Box Testing: Using Code structure to come up with test
cases.

White Box Testing:
Based on Internal Logic and source code.  

Black Box Testing:
Based on User requirements and functionality

Black Box testing: The software tester only knows what the 
system is supposed to do, he does not  know how it works 
internally.  He has to test on the basis of expected 
outputs.
E.g.: System Testing

White Box testing: The software tester has access to the 
program/ code and examine it for errors. Also called Clear 
Box testing or Structural Testing
E.g.: Unit Testing

Block box testing is done by the test engineers it means
that testing the application without knowing the structural
part of that with knowing the functional part of the
application.

whitebox testing :testing the application with knowing the
structural part of the application is called whitebox testing.