What's the difference

Whats the difference in between a Tera and Peta coaster. Or a giga and mega coaster

I don't know about the first two, but I do know about the second. Well, a giga coaster is one above 300ft, but a mega coaster has many different contexts. i belive Intamin reffers to there hypers as mega coasters, but don't quote that. It reall depends upon the designer for the mega coaster. Also i belive Morgan calls their coasters under 200ft mega coasters.

Tera is over 400ft.
Peta is over 500ft.
Giga is over 300ft.
Mega coaster is a range of sizes inbetween giga coasters and coasters that are about 150ft tall.

Just wanted to point something out it isn't just the height of the coaster that can define wether it is a hyper or Giga etc if the drop is over 200 or 300 etc
then the coaster can be classed as a hyper or giga etc, case in point Phantoms Revenge only stands 160 feet tall but has a drop of 228 feet.