Amateur Radio is a hobby or service where two-way radio enthusiasts study for and pass an exam to get a license from the government to learn more about radio and electronics on radio frequency bands that have assigned by the government for licensed radio hams to experiment with, to talk to each other and even to other licensed amateurs in foreign countries. The original amateur radio hobbyists had to learn enough about radio and electronics to build their own radios from scratch. And in the earliest years of amateur radio, the only way to 'talk' to anybody over the air was by sending and receiving signals in morse code.
So early ham radio operators had to study government regulations about how they could use their two way radios and know what they were not allowed to do, such as passing messages for third parties. They had to study all kinds of electronics theory, be good a mathematics and sit an examination to test their skills in receiving and sending morse code. But nowadays it is a whole lot easier...
For a start, radio hams only learn and use the morse code if they want to. It isn't mandatory any more, but there are still many amateur radio operators who use it and even love it. The electronics and radio theory examination has been made considerably easier - in fact it is a multiple-choice test. But licensed ham radio operators still have to pass n examination that shows they know and understand the rules and regulations of the Amateur Radio service.
One of the reasons that an Amateur Radio operator has to study and go through all these tests is because it is the Operator who is licensed in the Amateur Radio service. Whereas with other types of radios and other radio services such as business radio, CB radio or FRS radio, the government licenses the radio and not the person. So ham radio operators are given quite a bit of leeway to build two way radios, modify them, set up antenna systems and towers, and to experiment. With CB or FRS radio, the person themselves has not proved their skills and knowledge, so they are not allowed to modify their type-approved radios in any way.