Your salary is taxed in slices, not all at once at one rate. The first $18,200 you earn each year is completely tax-free. The next slice, up to $45,000, is taxed at 15%. Above that, the rate steps up again at $135,000 and again at $190,000, topping out at 45% on anything beyond that. Only the dollars sitting inside each bracket get taxed at that bracket's rate, so a higher salary never pulls your entire income into a higher rate all at once.
The Medicare Levy sits on top of income tax as a separate flat 2% charge on your taxable income, funding the public healthcare system. It isn't part of the bracket calculation above, it's added afterward, with a low-income cutoff below which it doesn't apply at all.
Superannuation works completely differently from everything else here. Your employer's 12% Super Guarantee contribution is never subtracted from your take-home pay, it's an extra amount paid into your super fund on top of your salary. That's why this calculator shows it as a separate line rather than folding it into your net pay figure: it's real money, just not money that hits your bank account today.