Layered authentication means requiring more than one check before a user is trusted. A password might be the first factor, but access can also depend on a one-time code, a device prompt, a hardware token, or a trusted workstation. The goal is simple: if one credential is stolen or guessed, the attacker still cannot pass every barrier.
In cyber security, layered authentication matters because stolen passwords, phishing, and social engineering are common entry points. A single login step is easy to defeat if an employee is tricked into revealing credentials. Adding extra checks reduces the value of one compromised account and can stop attackers from reaching email, file shares, or internal portals even after initial access. In defense, layered authentication is often paired with least privilege and device-based trust to limit how far an intruder can move if one control fails.