What is the difference between a JRPG and a WRPG?

[Mnementh]

I often see discussion about JRPGs and WRPGs. But nobody ever is clear about what makes the difference between the two. So please explain it to me: what makes the difference between JRPGs and WRPGs? Is it only the country of origin (in that case make statements like 'I like JRPGs over WRPGs' completely no sense) or is it about the gameplay? And if it is about gameplay, what are the defining differences?

To make it even more clear, you might classify the following games into one category or the other:
Rogue ( http://en.wikipedia.org/wiki/Rogue_(video_game) )
Nethack ( http://en.wikipedia.org/wiki/Nethack )
pedit5 (probably the first computer-RPG: http://en.wikipedia.org/wiki/Pedit5 )
Final Fantasy
Pokemon
Fire Emblem
Battle for Wesnoth( http://wesnoth.org/ )
Crimson Shroud
Denpa Men
Diablo
Heroes of Ruin
Tales of ...
Dragon Quest
Wizardry
Ultima
MUDs ( http://en.wikipedia.org/wiki/MUD )
World of Warcraft
Dragon Crystal
Etrian Odyssey
Baldur's Gate
Skyrim
Dragon Age