What is amateur radio?
Da-dit-da-dit da-da-dit-da
Since the end of the 19th century, technophiles everywhere have been playing with electricity and communication. This started as amateur telegraph operators creating their own wired telegraph networks, but when Guglielmo Marconi proved radio waves could be harnessed for communications, this quickly proliferated through troves of private tinkerers and experimentalists.
Amateur radio was born.
(Fun fact: this "clash" with professional telegraphers is where the term "ham radio" comes from! Amateur operators sending morse code sounded to their professional brethern hamfisted!)
What ever do we do?
Radio started with experimentation, but it was quickly adapted to transmit morse code, like wired telegraphs, allowing for practical communication. Throughout the early 20th century, figures like Hiram Percy Maxim (esteemed inventor of the car muffler and firearm silencer) began to create infrastructure for relaying messages through amateur radio systematically, with institutions like the American Amateur Radio Relay League (ARRL).
These figures and institutions created ways of sending morse code messages between hams, allowing actual communications and friendships to blossom over the air. With that said, experimentation remained at the heart of amateur radio, which meant hams continually strived to reach farther, better, in newer ways - a fact that kept amateur radio at the very forefront of radio technology throughout the first half of the 20th century.
"Contacts" could (and are!) as simple as exchanging who you are (identified with unique callsigns, in the case of BARS, W9YT), where you are, and whether you can actually hear the schmuck on the other end. These contacts were confirmed by sending QSL cards (postcards) back and forth, which could be kept for bragging rights! This has led to a rich award and contest culture which still exists in amateur radio today.
Cool...so why?
Well...it's cool to build an antenna and talk across the globe. Some people enjoy the challenge of simply reaching far away, others enjoy meeting people on the air and actually carrying on conversations.
Part of the initial proliferation of radio was that everyone wanted a slice - and thus, amateur radio, being one of the first users of radio spectrum, has a wide array of frequencies set aside for its use. This creates a sort of third-space on the air, where you never quite know who you'll meet or what they have to say...it's a ton of fun.
Some hams enjoy engineering and designing RF systems, others are in the hobby just to meet random people on the air. Both are equally valid uses of the radio spectrum!
Why amateur radio, instead of, say, CB or walkie-talkies?
Radio spectrum is divvied up into different "services", including amateur radio. The amateur radio service requires licensing - up to three classes to attain - but at the same time, gives the widest spread of spectrum a private user can use, with the very unique privilege of being able to legally design and use your own antennas/radios/ancillary equipment on the air! (Other radio users, e.g. CB radios, must be inspected by the FCC before use...not amateur radio!)
This has facilitated a very respectful and welcoming on-air community full of fun individuals to talk to and experiment with!