Penetration testing is a controlled process that simulates cyberattacks to evaluate an organization's security posture. It involves defining a test scope, gathering intelligence, analyzing vulnerabilities, attempting exploitation, conducting post-exploitation activities, documenting findings, and providing remediation recommendations. There are several types including external, internal, web application, wireless, and social engineering tests. Penetration testing plays a crucial role in identifying risks and enhancing an organization's cybersecurity, but proper authorization, methodology, documentation, communication, and continuous improvement are important best practices.