If software testing follows the principles of an agile model then it is called Agile testing. The agile model follows an incremental and iterative method where you keep on changing the requirements after each cycle.
Agile Testing saves time since you do not need to maintain lengthy documentation and also saves money. We will get regular feedback from the customer while implementing the project itself.
In Agile Testing, we keep on testing after each iterative and get feedback from end-users. Even the developers test the product not only the testing team in agile testing. In Agile Testing, the reusable checklist is used instead of lengthy documentation and testing is done while implementation.
In case you are interested in Agile, you can take up this Agile Training course by intellipaat.
You can watch this video to know more about Agile Testing: