FT8 is a signal encoding mode. My impression is that it is much more robust and therefore also reduces the required skill, luck, etc. in making successful trans

FT8 is a signal encoding mode. My impression is that it is much more robust and therefore also reduces the required skill, luck, etc. in making successful transmissions under unfavorable conditions. "DX" is an abbreviation for "distance", generally used in the sense of "making long-distance contacts." A "QSO" is a successful contact between stations, and "working" refers to the process of making / attempting to make contacts. "Multi-hop Es" refers to this atmospheric effect using the E region of the ionosphere: https://en.m.wikipedia.org/wiki/Sporadic_E_propagation https://en.m.wikipedia.org/wiki/Sporadic_E_propagation "CW" (for "continuous wave") typically refers to the use of Morse code over a constant frequency wave that's just being turned on and off, which has historically been one of the most robust modes, although it requires skill in encoding/decoding Morse by hand. "73" means "best regards" or similar; it's from very old telegraphy abbreviations.