Agile testing is a more collaborative and flexible testing approach
Waterfall software development meant a rigid testing process where testing was only done only once the development phase was complete. With agile development being so popular today, software testing teams must adapt to become agile testing teams. That means testing is being done on a more regular basis, with more flexibility, and more collaboration.
Agile testing is affectively testing software within an agile workflow. That means testing is not a separate phase; it is fluid and baked into the entire software development process. Often times cross-functional team members are involved in agile testing.