The word means two different things when you buy a home, and they are easy to confuse.
Your deposit for the loan is the part of the price you pay with your own money rather than borrow. It can come from savings, KiwiSaver, a gift or the sale of another property. Its size sets your loan-to-value ratio, which affects which lenders will consider you and the rate you are offered.
The purchase deposit is a payment made under the sale and purchase agreement. Depending on the agreement, it is paid once both sides have signed or once the agreement becomes unconditional, and at auction usually on the day. It counts towards the price at settlement, but because it is paid earlier, that money has to be available sooner than the rest.