How two-step sign-in works
Why a code is needed after your password, and which methods you can use.
Two-step sign-in asks for a second proof after your password. If someone steals your password, they still cannot get in without the code.
The methods
Authenticator app: an app such as Google Authenticator, Authy or 1Password makes a new code every few seconds. This is the recommended option.
Text message: a one-time code goes to your mobile number.
Email: a one-time code goes to your email address.
Recovery codes work once each if you lose your phone. Store them somewhere safe.
Who chooses
Administrators choose the permitted methods under Business Details on the Security tab, in Account 2FA preferences. You set up your own under Account Settings on the Security tab. See Set up two-step sign-in.
Up next
Next, read Locked out after wrong codes.