Short answer: TOTP uses the clock, HOTP uses a counter. TOTP codes expire every 30 seconds; HOTP codes stay valid until used. TOTP is what every website uses — here’s why, and where HOTP still survives.

Short answer: Settings → Security → Two-step verification → Enable, then choose “use a mobile app” over text messages. And store the backup codes anywhere except Dropbox itself — the mistake almost everyone makes.

Short answer: no bank, courier, buyer or support agent will ever ask for your verification code — not one, ever. Here are the seven scripts scammers actually use, the rules that defeat all of them, and what to do if you’ve already shared one.

Short answer: WordPress has no built-in 2FA — you add it with a plugin, enable TOTP, and save backup codes before you log out. Then close the two doors 2FA doesn’t cover: XML-RPC and application passwords.

Short answer: 2FA means exactly two factors; MFA means two or more. Every 2FA setup is MFA. Here is when the distinction actually matters — and why the more useful question is what each factor resists.

Short answer: account.microsoft.com → Security → Advanced security options → Two-step verification. Add an authenticator app, save the 25-character recovery code, and clear out the old phone numbers that quietly undo the whole thing.

Short answer: you need two independent layers — the app’s own backup (cloud sync or an encrypted export) and each service’s backup codes stored offline. Plus the one trick that only works while the setup QR is still on screen.

Short answer: Settings and privacy → Security and permissions → 2-step verification, then pick Authenticator app plus email. TikTok makes you choose two methods and issues no backup codes — which makes your recovery email the account’s real weak point.

Short answer: install the Steam mobile app, open Steam Guard → Add Authenticator, and write down the R-code before you tap past it. Steam uses its own five-character codes, so Google Authenticator won’t work — and the 15-day trade hold catches people out every time.