US stocks were mixed Monday and the S&P 500 eked out a record high for the sixth day in a row as investors digested the announcement of a trade deal between Washington and Brussels.

Tariffs are taxes charged on goods bought from other countries. Typically, they are a percentage of a product's value. So, a 15% tariff means that a $100 product imported to the US from the EU will have a $15 dollar tax added on top - taking the total cost to the importer to $115.