A multiple-entry Poland Schengen visa allows travelers to enter and exit Poland or other Schengen countries several times during the visa validity period. This type of visa is useful for people who travel frequently to Europe for tourism, family visits, or business meetings. The visa validity may range from 180 days to several years, depending on the decision of the embassy. However, even with a multiple-entry visa, travelers can only stay up to 90 days within a 180-day period in the Schengen Area.