Continuous testing is the software testing process of continuously ensuring the quality of the product at every stage of development. An integrated part of continuous integration and continuous deployment (CI/CD) process, continuous testing methodology enables early detection of issues, reduces developer feedback times, improves visibility of product quality, and accelerates goto market.
In older development models like waterfall, developers were siloed into separate teams focused on specific tasks. This led to a hand-off approach, where one team would finish its tasks and pass the software to another group. Quality was emphasized because each team had time to focus on its task without worrying about other aspects of the project.