What types of testing do you know?

Main types of testing:

• Functional testing — verifying that the functionality meets the requirements.
• Non-functional testing — checking performance, security, usability, etc.
• Unit testing — testing individual modules or functions.
• Integration testing — verifying interaction between modules.
• System testing — testing the entire system as a whole.
• Acceptance testing — verifying the product's readiness for use by the customer.
• Regression testing — ensuring that changes haven't broken existing functionality.
• Performance testing (load, stress testing) — testing under load.
• Security testing — checking for vulnerabilities.
• Usability testing — assessing interface usability.

Each type of testing addresses its own task and is often used in combination.