The confusion is even worse if you want to fly internationally. Official fares to most countries are set via a treaty organization called the IATA, so most computer systems list only IATA fares for international flights. It's easy to find entirely legal ``consolidator'' tickets sold for considerably less than the official price, however, so an online or offline agent is extremely useful for getting the best price. The airlines also can have some impressive online offers on their web sites.
Travel dates back to antiquity where wealthy Greeks and Romans would travel for leisure to their summer homes and villas in cities such as Pompeii and Baiae. While early travel tended to be slower, more dangerous, and more dominated by trade and migration, cultural and technological advances over many years have tended to mean that travel has become easier and more accessible. Mankind has come a long way in transportation since Christopher Columbus sailed to the new world from Spain in 1492, an expedition which took over 10 weeks to arrive at the final destination; to the 21st century where aircraft allow travel from Spain to the United States overnight.