What are travel visas?

Travel visas are 'conditional authorization granted by a polity to a foreigner that allows them to enter, remain within, or leave its territory'^[1]. They typically impose limits on the duration of the foreigner's stay, the areas they may enter, specific dates, and conditions regarding the number of visits or employment permissions within the country^[1]. Visas take forms such as a sticker in a passport, an electronic record, or a printed document, and they are subject to approval by immigration officials upon entry^[1]. Additional factors, such as financial security and health checks, may also influence visa applications^[1].