It means that it will not be necessary for the mobile to be on, with the internet or near these computers so that you can chat; the second is an optional tool to give your account more security, basically it will ask you for a six-digit PIN every time you log in.
Knowing this, it is important to clarify that currently two-step verification is only available on WhatsApp for mobile phones, since the app belonging to Meta (former Facebook Company) is still developing this important feature so that it reaches WhatsApp Desktop and possibly in the future WhatsAppWeb.
When the "Multi-device" mode is launched, it will be important to have two-step verification, so that no one can easily access the conversations in your account, reported the WabetaInfo technology portal.
WhatsApp Desktop: how to get two-step verification
As we said before, the function will arrive in a future update, it is not known where it will be located, most likely it will be in the “Settings” > “Account” section, so we recommend you get the beta version of WhatsApp for Windows and MacOS, remember that to be a beta tester the quotas are not limited.
When WhatsApp launches the new versions, you will only have to update the programs on your PC and mobiles, but not download them. Also, as a beta user you can enjoy the new features or changes that WhatsApp makes before they are officially launched.