Account security is the set of controls that protect access to a user account, especially strong passwords, password managers, multi-factor authentication (MFA), recovery protections, and alerts for unusual sign-ins. It helps ensure that only the legitimate owner can log in, reset credentials, or approve sensitive actions.
In cyber security, account security matters because stolen credentials are one of the most common ways attackers get in. Phishing, password reuse, SIM swapping, and session theft can all bypass weak login hygiene. Strong account controls reduce the impact of these attacks by making passwords harder to guess or reuse and by adding a second factor that an attacker is less likely to have. In privacy-focused cloud services, good account security is especially important because encryption can protect stored files, but it cannot protect against an attacker who can simply log in as the user.