what is Black Box Testing?

Black box testing is a software testing techniques in which
functionality of the software under test (SUT) is tested without looking
at the internal code structure

In Black Box Testing we just focus on inputs and output of the software system without bothering about internal knowledge of the software program.
 

The above Black Box can be any software system you want to test. For example : an operating system like Windows, a website like Google ,a database like Oracle or even your own custom application. Under Black Box Testing , you can test these applications by just focusing on the inputs and outputs without knowing their internal code implementation.

Black Box Testing and Software Development Life Cycle (SDLC)

Black box testing has its own life cycle called Software Test Life Cycle (STLC) and it is relative to every stage of Software Development Life Cycle.

• Requirement – This is the initial stage of SDLC and in this stage requirement is gathered. Software testers also take part in this stage.
• Test Planning  & Analysis – Testing Types applicable to the project are determined. A Test Plan is created which determines possible project risks and their mitigation.
• Design – In this stage Test cases/scripts  are created on the basis of software requirement documents
• Test Execution- In this stage Test Cases prepared are executed. Bugs if any are fixed and re-tested.