Free Trade is the absence of government restrictions or payments between individuals, businesses, and governments importing and exporting goods and services between different countries.
Examples of government restrictions are tariffs, subsidies, and quotas.
Example: China had been stealing intellectual property from U.S. citizens and businesses and preventing U.S. products from being sold in China or imposing tariffs on U.S. products. In an effort to discourage this behavior and to protect U.S. businesses in the meantime, the U.S. government imposed tariffs on Chinese goods.
Hopefully, China will refrain from further theft and the imposition of tariffs in the future so that there could be free trade between them with both nations operating on an even playing field.