Debit cards are similar to cash cards (also known as EFTPOS cards) but debit cards have more features.
Using a card is the most common way to pay here, even for small purchases. Contactless and mobile payments are becoming more popular too. In fact, New Zealand has the least cash circulating per person than any other OECD country.
Wages and salaries are usually paid directly into a bank account. If you have a job to come to, it is a good idea to open an account before you get here. You can transfer money into that account, but you cannot use it until you have verified your identity. Check how easy that will be when you choose a bank.