Chinesium - Cheap items made in China. Some work, some don't
H/T Handie Talkie or Walkie Talkie Hand held transmitting and receiving device. A portable two way radio. Railroad crews carry them and speak with one another.
Different stretches of railroad use different frequencies or channels depending on location. This information is available on a website -
http://on-track-on-line.com/amtrak-freqs.shtml
<50 - Less than Fifty Dollars US Currency
AMAZON - An online store from which you can buy almost anything and have it delivered to your door
Wouxon, Radiodity - Exemplars of Brand names on Chinesium H/Ts. Yaesu, Kenwood - also of Asian manufacture, but top quality and higher price
HAM - a sobriquet used to describe Licensed Amateur Radio Operators. HAMs find the hobby satisfying, educational, useful,enjoyable and a boon to society as they provide emergency communications during times of emergencies.
SWL _Short Wave Listeners - those who listen to radio communications on "short wave" radio frequencies. This includes the HAM frequencies, railroads, police, fire, dispatching and shorr wave worldwide communicaitons and broadcasts
Amateur License - A license American citizens can obtain from the Federal Communications Commission which allow you to transmit on certain frequency bands for noncommercial and educational purposes. Licensed operators are called "HAMs". There are several levels of licenses, each has additional bands or frequencies upon which you can transmit - voice, data, teletype, even television.
Morse Code is the system of communication devised my Samuel F B Morse. This is the system which uses short bursts of signal (Dit and dahs sometimes called dots and dashes when written) . One of the simplest and most reliable communication by wired or wireless devices.
Knowledge of and ability to use Morse Code was a prerequisite for obtaining an Amateur Radio License, now not required, alas
2 Meter and 6 Centimeters are bands of frequencies expressed in wavelength used for voice communication. Shot range, but there are many many devices called "repeaters" which pick up your signal and others, and rebroadcast them at higher power enabling longer range communication using voice - you can TALK directly to other people.
Duck Duck Go is a search engine which you can use for even more in depth explanation of this and other terminology you find. It is a replacement for Google, and does not track your inquiries for advertising or other purposes
I sincerely hope this helps to clear the fog out of your harbor.