Regression Testing - To verify that a code change in the software does not impact the existing functionality of the product. Smoke Testing - Identifying the business-critical functionalities that a product must satisfy. Sanity Testing - Sanity test is a narrow regression test that focuses on one or a few areas of functionality. Unit Testing - Unit Testing is a level of software testing where individual units/ components of the software are tested. Black Box Testing - also known as Behavioral Testing is a software testing method in which the internal structure/design/implementation of the item being tested is not known to the tester.