Donald Trump has said that “tariff” is the “most beautiful word in the dictionary.” And throughout his first months in office, the president has given Americans plenty of cause for googling that word’s definition.

Since January 20, Trump has announced tariffs on steel and aluminum made outside the US, all products made in Canada or Mexico, all Chinese goods, and all foreign-made cars, among other things. And on April 2 — a date Trump has dubbed “Liberation Day” — he has vowed to impose reciprocal tariffs on all nations that allegedly disadvantage US products through trade, tax, or regulatory policy.

The president’s prolific and haphazard tariff declarations have tanked stock markets, soured consumer sentiment, and thrilled some longtime critics of globalization.

Meanwhile, they’ve left some Americans concerned and confused; tariffs arguably haven’t been this relevant to the US economy in nearly a century. So many are understandably unsure about what tariffs are, how they affect consumers, why governments would implement them, and whether the president’s policy will work on its own terms.

Here’s the short answer: Tariffs are a tax on imported goods. They generally make affected consumer products more expensive. In theory, well-designed tariffs will also encourage targeted industries to produce more in the United States. And manufacturing certain goods domestically — instead of importing them from abroad —may have national security or economic benefits. Trump’s own rationales for his tariffs are numerous and shifting: The president sees them as a tool for raising revenue, enhancing national security, and revitalizing the US economy by increasing domestic manufacturing jobs. But the president’s tariffs are so broad, high, and ever-changing that they could actually backfire.

What are tariffs? How will they affect consumers?

To understand what tariffs are — and how they work — it’s helpful to consider a concrete example. On April 3, Trump will impose a 25 percent tariff on all cars made outside the United States. This means businesses that import foreign-made automobiles — such as car dealerships — will need to pay a 25 percent tax on every foreign vehicle that they purchase.

When a business’s costs rise, it typically tries to compensate by raising prices. And the president actually needs his auto tariffs to raise the prices of foreign cars: The official point of this tariff is to encourage Americans to buy more domestically produced cars, so that more auto manufacturers locate production in the US. If the tariff doesn’t make foreign-made cars more expensive for US consumers, it won’t give them any........

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