For example, if you earn $80,000, you will be in the $48,536 to $97,069 tax bracket with a tax rate of 20.5%. This means that you are taxed at 20.5% from your income above $48,536 ($80,000 - $48,536). Any additional income up to $97,069 will be taxed at the same rate. Any income beyond the upper limit will be taxed at the next tax bracket rate of 26%.
At $80,000, you will also have income in the lower two tax brackets: $0 to $13,229 and $13,230 - $48,535. Your income within those brackets ($13,229 and $35,305) will be taxed at their respective tax rates of 0% and 15%.
A common misconception is that when you go up to a higher tax bracket with a higher tax rate, you will have to pay more taxes on all of your income. That is not true. Only the additional income in the higher tax bracket will be taxed at the higher rate and your income in the lower brackets will be taxed at their lower respective rates.