No expert iswine but to put simply as understand it, if for...

No expert iswine but to put simply as understand it, if for example you spend $1000 to buy shares and you sell for $2000,
you made $1000 profit. If you held the shares for 12 months before you sold then you are entitled to a 50% discount on the profit so that means your taxable component is only $500. If you did not hold shares 12 months its still the full $1000 that is subject to CGT.

It then forms part of your overall taxable income for the financial year you sold. The CGT is then taxed at you taxable income rate. The amount you pay on the CGT is therefore different depending what tax rate you pay. Let's say you pay top tax rate of approx. 50% then the CGT will be $250(held over 12 months) or $500 (if held under 12 months).