Two-Factor Authentication (2FA) is a login method used by many cryptocurrency exchanges to increase security.
It generally requires the user to provide a second authentication using other information in addition to the regular login password.
The information required here varies from service to service, but it is usually through SMS, email, or authentication apps. Some services, such as online banking, use one-time passwords that can only be used once.
Two-step authentication does not completely prevent unauthorized logins, but it does increase the strength of security compared to passwords with only one step.
Even if your password or other information were to leak to the outside world, this system can prevent unauthorized access.
However, if you set the same password for your email service and the two-step verification service, the two-step verification will lose its meaning and the risk will increase.