The Schengen area is a group of 26 European countries that have abolished passport and immigration controls at common borders and have a common visa policy. It functions almost like a single country for the purposes of international travel, which, while allowing member countries to add their own special provisions for residence permits and local types of visas, ensures that certain types of visas are universal and that a person with a residence permit one Schengen country does not require a visa to visit or transit another Schengen country - in this sense it is very close to the common immigration policy of the European Union (the UK and Ireland are part of their own separate agreement called "common travel zone" and therefore the rules The Schengen Agreement does not apply there, although they are both part of the European Union (this is also given that the Schengen area also includes countries that are not members of the EU.). https://www.immigration-residency.eu/residence-permit-latvia/business-investment/