New Zealand Visitor Visa Guide & Assessment:

A visit visa is applied for New Zealand when you wish to enter in New Zealand for tourism, or visiting friends and family. If you do not intend to work and study during this temporary stay, then the visit visa is most apt for you. New Zealand also has a list of countries whose visa has been waived off, so, if you reside in any of those, then you can enter New Zealand without the need to have a visa. If, however, you are not in a country with the visa waived off, then you will need to acquire a visa to enter New Zealand.
Persons; with a permanent New Zealand or Australian address, part of a diplomatic mission, military occupation, member of the commercial flight group or Antarctic travelers, do not need to acquire a visa before entering into New Zealand.

There are two kinds of visitor visa for New Zealand. The actual visit visa, with a maximum time frame of 18 months can be acquired by people wishing to visit New Zealand. You will need to meet all the necessary requirements outlined by the New Zealand government. You should; be in good health, have a valid passport, have sufficient funds for the trip(NZ$1000 /person/month), have a clean police record, and have a planned and paid trip out of New Zealand.
If, you fail to meet the above criteria, then you will not be able to acquire the said visa.
If, you are planning to pass through New Zealand, then you are not required to possess a visitor visa. A transit visa is issued for persons who will be staying within the premise of the airport and for less than 24 hours. You do not require to possess a transit visa for passing through New Zealand if you belong to the following countries; Bahamas, Bermuda, Bolivia, Colombia, Costa Rica, Ecuador, Federated States of Micronesia, Papua New Guinea, Paraguay, Peru, Philippines, Republic of Marshall Islands, Samoa, Indonesia, Kiribati, Nauru, Palau, Panama, Thailand, Tonga, Tuvalu, Vanuatu, Venezuela and Solomon Islands. If you are passing through New Zealand to enter Australia legally, then you are not required to possess a transit visa. Being a citizen of the states whose visa has been waived off you also do not require a transit visa.