Ive been a DX'er since 1949!!
DX is listening to Long distant Radio Signals, either LW, MW, SW, or VHF and UHF.
Ive loged over 120 Countries and got QSLS from over a 1,000 stations on SW and 103 Countries on MW with 600 QSL's received...(including several 1st Reports from NZ)
DX is the Radio Term (Ham)for "Long Distance".
I consider in my case Stations at least 1,500 miles or more from my QTH as DX, (even 0n the "Degen DE1125" with its whip I get many European and South American Stations)
Its all down to LISTENING.