Aussie Tax Law v NZ, page-2

When I lived in NZ 20 years ago, there was no capital gains on share sales

This is/was often mis-understood, even by Kiwis, and especially by Aussies who are used to CGT

"we only pay tax on the dividend" is not correct

No capital gains tax but income from selling shares was added to your other income eg to wages income

In Australia it depends on whether you are a trader or investor as to what tax you pay and whether you are entitled to any CGT idiscount

There are several threads on trading/investing and also, Google is your friend