What is password/passphrase/PIN code and what they are used for?

Password, passphrase and PIN are not the same thing since they are used for different purposes.

Password is used for logging into account, whereas passphrase is used for confirmation of the account ownership. A passphrase is the last option to recover your account if you've lost password and email and forgot username. PIN is used for applying changes made in your account settings.  

Password and PIN sent to your email during registration and also are shown on the first login to your account. We strongly recommend to change your password to a more complex one due to security reasons. Keep this new password in a safe place. Once you do this, delete email containing your registration data and also empty Trash section.

Never disclose your registration info to anyone. Our support officers most likely will ask you to provide your passphrase, but they will never ask about your password or PIN. Even if they will ask about your passphrase, they can do it solely via our Ticket Support Center (http://8bsupport.com) or Live Chat. Do not respond to any emails asking to provide your password/passphrase/PIN even if the mail sender is stated to be 8bit.ltd. It is against our privacy policy and company regulation to request such information via unreliable means of communication like email. You can be sure that person asking to share your account information is a malefactor.