A more thorough explanation:

The Madrid Protocol is an international agreement that allows citizens of a Madrid Agreement signatory nation to apply for a single international trademark through the World Intellectual Property Organization instead of registering the trademark in each individual nation. This means that if someone wants to register a trademark in multiple countries, they can do it all at once instead of going through the process in each country separately.

For example, if a company in the United States wants to register their trademark in Canada, Mexico, and Japan, they can do it all at once through the Madrid Protocol instead of having to go through the registration process in each country separately.

The Madrid Protocol requires that an applicant must apply for the trademark's registration in a treaty-member nation before applying for international trademark protection. This means that the applicant must first register their trademark in their home country before applying for international protection.

The Madrid Protocol is sometimes also referred to as the Madrid System when referred to along with the Madrid Registration of Marks Treaty.