A basic understanding of aviation regulations helps to understand some of the most basic requests airlines make of their passengers. Air travel is hailed as one of the safest modes of transportation not only because of the advancements in technology and the training that the aviators go through before they get a seat in the cockpit, but also because of the many regulations that bind it. Understanding the basis of a particular regulation is necessary to elucidate why the requirements exist, although the pressures of travel on passengers may make them seem arbitrary or unwarranted.