1) if by general names u mean wat r they called, they r just the names of the systems that the companies made to make the engines breathe better by variating the timing of the opening and closing of valves, spark plug firing, lift of the valves, etc.
2) others ones would be the VTC (by nissan), and i forgot the name of the ferrari one.
3) V-TEC stands for something like Variable Valve lift and control Timing Electronnically Controlled or something like taht.
VVT-i is Variable Valve Timing with intelligence
VTC - Valve Timing something
so on so on, just search in google.com, its easy to find.
4) read the first explanation i gave, thats generally the basic idea.
5) i dont get wat u mean by wat makes them different.
6) the better the engine breathes, the more efficient it is, meaning the more power it can make with the less amount of work, if not the same amount of work. also, the less pollution it causes.
7) the one with the best controlling performance and the one that controls the more aspects possible of the engine is the best.
8) not sure which one is the best, v-tec only controls the opening and closing and the lift of the valves. others control spark plug timing, others do both but on exhaust side or the intake side only, etc. google.com can answer this
Supra: To surpass or go beyond.