Final answer:
Regression testing is a quality assurance process where modified software is tested to confirm that changes have not introduced new defects and that the software continues to comply with its specified requirements.
Step-by-step explanation:
The testing you are referring to is called regression testing. Regression testing is a type of software testing that ensures that recent program or code changes have not adversely affected existing features. It verifies that modifications in the software or the environment have not caused any new defects. This is an integral part of the quality assurance process in software development.
During the design and development phase, prototypes may undergo testing and evaluation to reveal any weaknesses and to ensure that the design meets the necessary constraints and criteria. If modifications are made to a prototype or a software component based on these evaluations, regression testing is performed to reaffirm that the updated design or code still adheres to its originally specified requirements.