Capital gains tax (CGT) is the tax you pay on any capital gain you include on your annual income tax return. It is not a separate tax, merely a component of your income tax. You are taxed on your net capital gain at your marginal tax rate.
Your net capital gain is:
your total capital gains for the year
minus
your total capital losses for the year and any unapplied net capital losses from earlier years
minus
any CGT discount and small business CGT concessions to which you are entitled.