Functional Testing: It’s a mandatory testing level, during this Test the testing team is validating a software build functionality in terms of below factors with respect to customer requirements.

  1. Behavioral / GUI: The changes in properties of Objects OR controls in a software is called behavioral or GUI.
  2. Input Domain: Whether the Objects are taking correct type and size of inputs or not?
  3. Error Handling: Whether our software is preventing wrong operations or not?
  4. Manipulations: Whether our software is generating correct output or not?
  5. Database Validity: Whether our software front end screens operations are correctly impacting on database of the software or not?
  6. Sanitation: Finding extra operations in a software with respect to customer requirements.

The above factors checking on a software is called as functional testing. During this checking the testers are using black box testing techniques or closed box testing techniques.