In one sentence: Two-factor authentication (2FA) is a second check, after your password, that shows it is really you.
Why it matters: If someone steals your password, they still need the second step. In the UK and in Google settings, it may be called 2-step verification (2SV). It makes an account harder to take over.
One thing to do: Open the security settings of your main email account and turn on 2-step verification. Choose a passkey or an authenticator app if offered.
Related terms: multi-factor authentication, authenticator app, passkey
Learn more: Two-Factor Authentication (2FA): What It Is and How to Turn It On
Checked: 25 Oct 2026. Settings screens change. If yours looks different, search the company's help page.
