Customs duties, or tariffs, have become a political punching ball as the European Union prepares to respond to US President Donald Trump's recent offensive.

But what exactly do we mean when we talk about tariffs? How does the EU policy work? Who pays them and what are they for?

Some answers:

Used by almost every country, tariffs are a tax on products imported from abroad.

They take many forms, the most common being a percentage of the economic value of the product -- the "ad valorem" duty.

The EU, like other economies, also uses so-called "specific" tariffs, such as an amount set per kilogramme or per litre of any given product.

Globally in 2022, the average tariff was 3.6 percent, according to the CCI-Cepii database (Centre for Prospective Studies and International Information).

In other words, each product crosses a border at a price 3.6 percent higher than its cost domestically.

"This average figure hides very strong differences between countries and sectors," Houssein Guimbard, a trade policies specialist at Cepii, told........

© International Business Times