International Telecommunications Union (ITU) - This is an agency of the United Nations that establishes rules for radio communication all over Earth.
International Amateur Radio Union (IARU) - An international confederation of national organizations that are responsible for amateur radio rules in their own countries.
Ham Radio Operators - Ham used to mean “ham-fisted”, a term used to refer to amateur radio operators in the early ‘90s because they were considered a nuisance. HAM is sometimes mistaken to be an acronym for Hobby Amateur.
Homebrewing - Making your own equipment to be able to use within the amateur radio service
Contesting - Oftentimes, contests are held within ham radio communities to see who can establish contact with the most number of people the fastest. This is usually done with handicaps on the frequencies used, the technologies used, etc
Emergency Communications - Using ham radios during emergencies is often helpful
Radiotelegraphy - Communicating over radio using morse code
CW - Continuous wave, or simply morse code.
Q Code - The specific language of morse used in radio communications
FM - Frequency Modulation, one of the most common transmission techniques in ham radio
Single Side Band (SSB) - A modified version of AM that is better for long distance communication and when bandwidth restrictions are high
AM - Not used a lot any more because of high bandwidth
Shortwave Radio (SW) - Essentially another term for HF
High Frequency (HF) - A band encompassing 3-30MHz
Very High Frequency (VHF) - A band encompassing 30-300MHz
Ultra High Frequency (UHF) - A band from 300MHz-3GHz
Teleprinter/Teletype/Teletypewriter/TTY - Basically, two typewriters connected at a very long distance through wires, where typing on one prints out a message on the other end.