Penetration testing, often called pentesting, is an authorized simulated cyberattack on a computer system performed to evaluate its security. The primary goal of penetration testing is to identify weaknesses or vulnerabilities that unauthorized parties could exploit to gain access to the system's features and data, thereby enabling a full risk assessment to be completed. It can involve testing various aspects of a system, including networks, web applications, wireless networks, and social engineering vulnerabilities. Penetration tests can be conducted with different levels of information about the target system, such as white box (full knowledge), black box (minimal knowledge), or gray box (partial knowledge). The testing process typically includes phases like reconnaissance (gathering information), scanning for vulnerabilities, gaining access through exploitation, maintaining access, covering tracks, reporting findings, and retesting after remediation. Penetration testing helps organizations discover security flaws before malicious hackers do and supports compliance with security regulations by ensuring controls are effective. It is a proactive approach to cybersecurity to strengthen defenses against potential cyberattacks.