A pentest, or penetration test, is a controlled and authorized simulated cyberattack on a computer system, network, or application. Its purpose is to identify vulnerabilities and weaknesses before malicious hackers can exploit them. Security experts, known as ethical hackers, use the same techniques as real attackers to test defenses, document findings, and recommend improvements. Pentesting helps organizations strengthen their security, comply with regulations, and protect sensitive data by addressing risks proactively.