Name the types and levels of testing.

Types of testing:

• Functional testing — verifying that the functionality meets the requirements.
• Non-functional testing — verifying performance, security, usability, etc.
• Regression testing — ensuring that changes haven't broken existing functionality.
• Acceptance testing — verifying the readiness of the product for release.

Levels of testing:

• Unit testing — testing individual functions or components.
• Integration testing — testing the interaction between modules.
• System testing — testing the entire system as a whole.
• Acceptance testing — testing the system from the user's or customer's perspective.