An income tax is money that people and businesses must pay to the government based on how much they earn. If your parents work and earn a salary, they pay a percentage of that money as income tax. If someone earns $50,000 in a year, they might owe $10,000 in income tax, depending on the tax rate and rules where they live.

Governments use income tax revenue to pay for things that benefit everyone: roads, schools, parks, the military, and programs that help people in need. Income tax is one of the main ways governments around the world raise money to operate, alongside other taxes like sales tax (added when you buy things) and property tax (paid by homeowners).

Many countries, including the United States, use a progressive system, meaning people who earn more pay a higher percentage. Someone earning $30,000 might pay 10% in income tax, while someone earning $300,000 might pay 30% or more on part of their income. This system tries to balance fairness: those with greater ability to pay contribute more.

People typically file their income taxes once a year, when they calculate exactly how much they owe and either pay additional money to the government or get a refund if they already paid too much.