Using the standard security procedures (username and password) has become easy for criminals to break into peoples’ accounts.
2FA is an extra layer of security that requires an additional piece of information which is generated only on a secondary device of your choice. The most common example is when you do online banking. In most cases, the bank sends you an SMS or calls you sometimes to confirm that it is you indeed who’s doing a transaction.
Most cryptocurrency exchanges support this option as well these days. Connecting your phone, via a 2FA app, is a widely available option. Once connected, the app generates a new code every 30 seconds, therefore, increasing your level of security.