According to the IRS, income includes money, property or services. Any income is taxable unless the law specifically exempts it, and all taxable income must be reported on your tax return. Some nontaxable income must be reported, too, even though you won’t pay taxes on it.

IRS Publication 525 has details on what counts as taxable income and what doesn’t, and it’s a lengthy list. Not all taxable income is treated the same. Earned income, like your wages, is taxed differently because you pay Social Security tax, Medicare tax, and state and federal income taxes on it.

Unearned income, like child support or Social Security benefits, isn’t subject to payroll taxes, but you do pay federal and sometimes state income tax on it. And some types of unearned income are taxed at a lower capital gains rate, rather than your normal tax rate.