5. Itemized deductions: These are expenses that can be deducted from your AGI to help you reach a smaller income amount upon which you must calculate your tax bill. Itemized deductions include medical expenses, other taxes (state, local and property), mortgage interest, charitable contributions, casualty and theft losses, unreimbursed employee expenses and miscellaneous deductions such as gambling losses. Some itemized deductions must meet IRS limits before they can be claimed. When you itemize, you must file Form 1040 and detail your deductions on Schedule A.

6. Exemption: This is an amount the IRS lets you subtract from your income to reflect all the people who count on your income. Exemptions can be claimed for yourself, your spouse and your dependents. The IRS allows a set amount for each exemption and, as with deductions, this total is subtracted from your adjusted gross income to come up with your final, lower earnings amount upon which you must figure your tax bill. Your personal exemption amount is in addition to any deductions, either standard or itemized, that you claim.

7. Progressive taxation: This is the system in which higher tax rates are applied as income levels increase. The U.S. tax system uses progressive taxation with tax brackets starting at 10 percent and rising to 35 percent for the wealthiest taxpayers.

8. Taxable income: Your overall, or gross, income reduced by all allowable adjustments, deductions and exemptions. It is the final amount of income you use to figure out how much you owe in taxes.

9. Voluntary compliance: This describes the philosophy upon which our tax system is based: U.S. taxpayers voluntarily comply with the tax laws and report their income and other tax items honestly.

10. Withholding: Also known as pay-as-you-earn taxation, this method enables taxes to be taken out of your wages or other income as you earn it and before you receive your paycheck. These withheld taxes are deposited in an IRS account and you are credited for the amount when you file your return. In some cases, taxes also may be withheld from other income such as dividends and interest.

For a complete list of tax terms, check out our tax glossary.