A pasajes aéreos is Spanish for a plane ticket. But what is a plane ticket for? A plane ticket is proof that you can go on holiday with that flight. That ticket states the destination, how long you are going. You can show this when you board the plane together with your passport. Bringing your passport to the airport is important, you need it to identify yourself. This way they know that it is you and they can compare the name on the pasajes aéreos and your passport. Identity fraud is therefore certainly not tolerated at the airport.
If this does happen, the intention is for the police to take action and then you can say goodbye to your trip. Now there are different kinds of reasons why you should travel by plane. Sometimes there is no other option because it is impossible to do with a boat or car. With a boat you can sometimes be on the road for months with long distances. A car cannot go over water so there is only one thing left to do. There are also business trips, this is flying for work. But all in all, it is of course the best to just have a wonderful holiday.