Interesting. What’s the difference?
Spelunker is a term invented by the media, Cavers have a saying, “cavers rescue spelunkers”.
Spelunkers are usually unprepared. Being unprepared, means only having one source of light, no helmet, wearing tennis shoes, wearing one layer of cotton clothes in a wet cave, getting lost or trapped during a rain due to high water, going down a pit with no descending/ascending equipment or experience and usually not having any food or water with them. A lot of spelunkers are usually high or drunk too and they often carry cans of spray paint with them. They also kill bats and break formations.
Real cavers take their sport seriously and prepare accordingly. Most caves are on private land and we have to get permission from the landowners to enter their caves. There have many caves closed due to stupid crap done by spelunkers.