Final answer:
Taxable income is the income on which tax is paid after deductions are subtracted from one's gross income.
Step-by-step explanation:
The subject of the question is taxation. Taxation is the process of imposing a financial charge or other levy upon a taxpayer by a government or other taxing authority in order to fund various public expenditures. In this case, the question is referring to taxable income, which is the income on which tax is paid after deductions are subtracted from one's gross income.