The newly deployed code is rechecked in order to ascertain the impact of updations, modifications or changes done to the code through the regression testing method. The features and functions of a product are tested in order to ascertain whether the product is built according to the product specifications through the functional testing method. In this article, you will know about the differences between regression testing and functional testing.     What is Regression testing ? It is a testing method that ensures that the modifications, updations or changes done to the code don’t affect the existing functionalities of the software application. Already executed test cases that are partially or fully selected are re-executed to ensure that the existing functionalities work just fine. Whenever the requirement arises for making changes in the code, the modified code needs to be tested in order to ensure that other parts of the software application are not affected. Even a small tweak i