A student visa is the approval you need in your passport to enable you to travel to New- Zealand to study.
It is the requirement by law that you will need a student visa if you are in New- Zealand and want to travel overseas and return to New-Zealand to study.
The student visa gives you permission to travel to New-Zealand and means that you may be granted a student permit when you arrive.
The student visa also means that you can be issued for a single(one journey0 or multiple(more that one journey) entry.
What is student permit?
A Student permit is the signature in your passport that acknowledges your right to study in New- Zealand. It will state the expiry date and give the circumstance of your permit.
The circumstance of your student permit will include details about:
The course you are studying.
The educational institute that you are studying at.
The address of the institute in New-Zealand.
And any other restrictions (such a not being permitted to work).
Who needs a student visa?
You will need a student visa if you are not a resident in New Zealand, and are coming to New Zealand to study full time(for longer than three months. Your spouse, or partner and children who would like to go with you can apply for visitor or student visa.
Possible student coming as visitors to New Zealand from visa free countries may apply for a student permit once an educational institute has accepted them.
Who need a student permit?
Workers and visitors in New Zealand that want to study full time.
People that wish to extend their study or training.
Anyone who’s spouse is in New Zealand on another type of temporary permit i.e work permit.
Children to study while their families are in New Zealand.
How do I apply for a student visa or permit?
Full details of visa and permit requirements, advice on rights to employment in New Zealand while studying and reporting requirements are available through the New Zealand immigration service.
Do I need medical insurance?
Generally, students are not entitled to publicly funded health care while they are in New Zealand, unless they are:-
A resident or Citizen of Australia.
National of the United Kingdom in New Zealand.
They hold a temporary permit that is valid for two years or more.
For advice on eligibility and entitlement, please refer to ministry of Health web site
Do I need a police certificate?
If you are 17 years of age and over and intend to stay in New Zealand for a total of more than two years, you must provide a police certificate to show you are of good character. In order to prove you are of good character, you must supply the following:-
A police certificate from you country of citizenship.
Police certificate from any country you have lived for five years or more since reaching the age of 17 years.
Your police certificate must not be more than six months old at the time your application is lodged.
With a worldwide reputation as a first-class education provider, over180,000 students from around the globe flock to Australian shores annually . . . .
Canada
World Wide Education Services (WWES), the overseas education division of WWICS, has assisted hundreds of students to opt for higher studies in countries like USA, UK . . . .
Skilled Workers 
