An excise tax is a special tax charged on specific goods or activities rather than on all purchases. Unlike sales tax, which applies to almost everything you buy, an excise tax targets particular items: gasoline, cigarettes, airline tickets, or soda in some places.

Governments use excise taxes for two main reasons. First, they raise money for specific purposes. The federal excise tax on gasoline, for example, helps pay for building and maintaining highways. Second, excise taxes sometimes discourage people from buying things that might be harmful, like tobacco products.

You usually don't see excise taxes listed separately on a receipt the way sales tax is. Instead, they're already built into the price. When you see gas priced at $3.50 per gallon, about 50 cents of that is federal and state excise taxes, though the price sign doesn't break it down for you.

These taxes have existed for centuries. England had an excise tax on salt in the 1600s, and American colonists protested excise taxes on items like tea, which helped spark the Revolutionary War. Today, excise taxes remain an important way governments fund specific programs while influencing what people choose to buy.