Functional Testing is important to assure the quality of software before its release. The testing examines how your hardware, software, Website, and/or internal application performs its expected functions. This rapid series of tests validates the behavior of the application by applying a wide range of regular and also incorrect input data to see how the software responds in every instance.
Unit testing is the first level of software testing used to validate that each software unit performs as designed.
Integration Testing is the second level of software testing used to expose defects between integrated units.
System Testing is used to review complete and fully integrated software product behavior for potential bugs and complications.
Regression Testing ensures any changes and previous programming functions are intact with the latest updates applied.