Black box testing is testing the application from a 
functionality perspective with respect to the requirements.

There are different techniques for black box testing which 
includes Equivalence Partition, Boundary Value Analysis 
etc.,

Black-box test design treats the system as a "black-box", so
it doesn't explicitly use knowledge of the internal
structure.  Black-box test design is usually described as
focusing on testing functional requirements.  Synonyms for
black-box include:  behavioral, functional, opaque-box, and
closed-box.  White-box test design allows one to peek inside
the "box", and it focuses specifically on using internal
knowledge of the software to guide the selection of test data.

Black Box Testing is testing the application with the 
testcases that are prepared from the Requirements. 

In Black Box Testing, Tester will not have the knowledge of 
coding.

Black Box testing is five types.

1) Boundary Value Analsys.
2) Equilence class partitions.
3) Error Guessing.
4) Cause effect graffing.
5) Orthoganl arrays.