Some of my "non-psy-fan" friends call Psy-Trance as Hard-Trance (well sometimes it's pretty hard i'd say)
It always encourages me to explain a bit to them, and every time they get the point better and better - so it's a pretty broad term "Psy Trance".
So many things are connected - i'd say it's not just music, it's also a way of partying with all the decorations around, the freaky people on the dancefloor and of course the SOUND itself - this whole builds PSY culture.
The most important thing are special samples which are used in Psy-Trance music - not just bassline, but also the string-lines, the 303's (my favourite), nature sounds, the bongos and congas, and so many others.
And of course don't forget where did it come from - the holy land of GOA
to be continued...