Tax systems fall into two main categories within the tax code: regressive and progressive taxes. Regressive taxes are those that have the greatest impact on low-income individuals rather than high-income earners. It is an equal aliquot, but that proportionally affects those who have lower income. For example, the food tax takes a larger share of a poor person's income than a millionaire.
A progressive tax has more impact on individuals and companies with higher incomes and less financial impact on low-income earners. For example, to collect the income tax, you can institute a higher aliquot, the higher the income.
In sum, a regressive tax on the poorer citizens, as the progressive tax charges more of those who have higher income, which is fairer.