Countries have visa restrictions in order to check and control the flow of visitors in and out of the country and to prevent illegal immigration and other criminal activities. Forcing travellers to apply for a visa allows the authorities to vet potential visitors. For example, individuals may attempt to travel to a country with better economic opportunities in order to work illegally there.
Each country has its own visa application requirements. Make sure to check with your destination country’s appropriate government website to find out. Requirements typically include filling out the visa application form, providing your passport for stamping if required, a photograph, and additional documents such as your flight itinerary, hotel booking or letter of invitation.
Due to a state of war existing between Armenia and Azerbaijan, the government of Azerbaijan not only bans entry of citizens from Armenia, but also all citizens and nationals of any other country who are of Armenian descent, to the Republic of Azerbaijan (although there have been exceptions, notably for Armenia's participation at the 2015 European Games held in Azerbaijan).
Citizens of member states of the Association of Southeast Asian Nations do not require tourist visas to visit another member state, with the exception of Myanmar. Until 2009, Burmese citizens were required to have visas to enter all other ASEAN countries. Following the implementation of visa exemption agreements with the other ASEAN countries, in 2016 Burmese citizens are only required to have visas to enter Malaysia and Singapore. Myanmar and Singapore had agreed on a visa exemption scheme set to be implemented on 1 December 2016. ASEAN citizens are entitled to use the Burmese visa on arrival facility.