Exchanges Here are all the Bitcoin exchanges currently available in New Zealand for buying and selling Bitcoins. An exchange is a market place where you can buy and sell Bitcoins with other traders. There are normally two prices, the buy price and the sell price. The order book is a collection of the lowest buy prices and the lowest sell prices available. None of these exchanges are regulated as such, so you use them at your own risk. Two Factor Authentication (2FA) 2FA is a secondary login password provided by another device, this could be an email to another email account other than your primary account, or an SMS message, or you can use an app on your phone such as Google Authenticator to do this. This means that even if your password or email is compromised, the attacker would also have to compromise your secondary authentication method as well to hijack your account. Application Programmer Interface (API) An API allows you to control your account or access the exchange with a computer program. This can allow you to use mobile apps or external services to interface with the exchange more easily.