How to travel to South Island and North Island of New Zealand?

South Island is fun, most of New Zealand's scenic spots are in South Island, and North Island is mainly for leisure and vacation. Volcanoes, geothermal, caves, fireflies, beaches, bays, dolphins, waterfalls, trees and pastures are the most beautiful. South Island takes fjords, mountains, glaciers, vineyards, pastures, lakes and whales as its main sightseeing scenery. More desolate and natural. Located at the southernmost tip of the North Island, the capital of New Zealand is an important hub connecting the two islands.