In some countries, non-local internal travel may require an internal passport, while international travel typically requires a passport and visa. Examples of travel tours are expedition cruises, small group tours, and river cruises. Travel by water often provided more comfort and speed than land-travel, at least until the advent of a network of railways in the 19th century. Travel for the purpose of tourism is reported to have started around this time when people began to travel for fun as travel was no longer a hard and challenging task. This was capitalized on by people like Thomas Cook selling tourism packages where trains and hotels were booked together. Airships and airplanes took over much of the role of long-distance surface travel in the 20th century, notably after the Second World War where there was a surplus of both aircraft and pilots.
According to Notification of Medical Surveillance, it is an …