An Interim Visa allows you to stay in New Zealand while we assess your application for another temporary visa.
You must have applied for another temporary visa before your previous visa expired. You don't need to apply for an Interim Visa - INZ usually grant them automatically. An Interim Visa may allow you to continue working or studying – it'll depend on the visa you've applied for and the visa you had before.
For more information, visit the Immigration New Zealand website