Taxes, in some form, have been around since the beginning of civilization and, whether you know it or not, they impact just about every aspect of our lives. But how much do you really know about taxes? What are they for? What different types of taxes are there? How do they affect behavior, business, and what’s in your pocket? Taxes may be a fact of life, but they’re certainly not simple. That is why Tax Foundation launched Tax Basics, a resource for learning about and understanding various forms of taxes, how they work, and how they impact you.

Term of the Month

Global Intangible Low Tax Income (GILTI)

Global Intangible Low Tax Income (GILTI) is a special way to calculate a U.S. multinational company’s foreign earnings to ensure it pays a minimum level of tax. GILTI was adopted as part of the 2017 Tax Cuts and Jobs Act (TCJA) and can lead to high tax burdens on foreign profits, putting U.S. companies that operate abroad at a disadvantage.


Featured Terms

Book Income

Corporate Income Tax

Full Expensing

Gross Receipts Tax

Step-Up In Basis

Net Operating Loss Carryback

Foreign Derived Intangible Income (FDII)

International Tax Rule

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Glossary of Terms

Adjusted Gross Income (AGI)

After-Tax Income

Alternative Minimum Tax (AMT)


Average Tax Rate

Base Broadening

Base Erosion and Anti-Abuse Tax (BEAT)

Bonus Depreciation

Book Income

Bracket Creep

C Corporation (C corp)

Cadillac Tax

Capital Gains Tax

Carbon Tax

Child Tax Credit (CTC)

Corporate Income Tax

Cost Recovery


Double Taxation

Dynamic Scoring

Earned Income Tax Credit (EITC)

Estate Tax

Excise Tax

Foreign Derived Intangible Income (FDII)

Full Expensing

Global Intangible Low Tax Income (GILTI)

Gross Receipts Tax

Head Tax

Individual Income Tax

Inflation Indexing

Inheritance Tax

International Tax Rule

Internet Sales Tax

Itemized Deduction

Marginal Tax Rate

Marriage Bonus

Marriage Penalty

Mortgage Interest Deduction

Net Operating Loss Carryback

Net Operating Loss Carryforward

Pass-through Business

Pass-Through Business Deduction (Sec. 199A)

Patent Box

Payroll Tax

Pigouvian Tax

Progressive Tax

Property Tax

Refundable Tax Credit

Regressive Tax


S Corporation

Sales Tax

South Dakota v. Wayfair

Standard Deduction

State and Local Tax (SALT) Deduction

Static Scoring

Step-Up In Basis



Tax Base

Tax Bracket

Tax Credit

Tax Cuts and Jobs Act (TCJA)

Tax Deduction

Tax Exemption

Tax Expenditure

Tax Pyramiding

Tax Refund

Taxable Income

Territorial Tax System

Value-Added Tax (VAT)

Wealth Tax


Worldwide Tax System