A penetration test, or pentest, is a security assessment that involves simulating a real attack on a computer system, network, or application in order to identify exploitable vulnerabilities. The goal is to detect weaknesses before an attacker discovers them, and to provide concrete recommendations to strengthen security.

Unlike purely documentary audits, a pentest relies on offensive techniques similar to those used by hackers. It may include exploiting software flaws, compromising accounts, or traversing firewalls. It is often performed in addition to an automated scan to assess not only the presence of vulnerabilities, but also their actual exploitability in the target context.