Functional testing focuses on verifying an application's functionality against its requirements and specifications, whereas non-functional testing examines how well or poorly an application behaves, including aspects such as performance, security, scalability, compatibility, user experience, and localization. Functional testing techniques include unit testing, acceptance testing, integration testing, regression testing, and visual testing, which test various components of the application at different levels, from individual units to entire workflows. Non-functional testing encompasses performance testing, security testing, compatibility testing, and user experience testing, each aimed at evaluating specific aspects of an application's behavior. Automation is crucial for both types of testing due to their complexity and the need to cover a wide range of scenarios, making test automation tools essential for delivering effective testing results.