Not much is known about the origin of this strange world, but since it's directly parallel with the original Starcraft world, its birth was around at the same time. Terran scientists have discovered unkwown alien tablets, and with the help of some friendly protoss (protoss can read virtually any wriiten language), they revealed stories of this mythical realm. E.I.U. (Extraterrestial Investigations Unit) have conducted further research, and revealed new races of exterrestial life, only existing in this parallel universe.
Just because it's a parallel universe, it doesn't nececcsarily mean there's going to be directly opposite events. For example, a new swarm of zerg, under the control of a new Overmind, was discovered in this world, and they're still vicious and brutal as our zerg. Also, protoss artifacts have been recently discovered in this alternate realm, indicating the existence of protoss as well as zerg. However, we have not discovered actual protoss life-forms yet, just artifacts. Since the Dominion or the Raiders haven't sent any human being to this world, there is no terran life present. However, a new race exists here, and it pretty much "fills in" the spot for terrans as one of the 3 main races in this parallel universe. They are also strikingly humanoid, as well as being extremely advanced in the ways of architechture and technology. But they are much more savage and fiercely loyal to each other. They are known to be called Savagoids. There are also a LARGE number of star systems and planets, as well as huge chunks of unexplored space. Also, the other races undiscovered by man, are slowly revealing clues. Also, Samir Duran was known to have disappeared ever since he was revealed as a spy for Kerrigan. Rumors suggest he may have gone to this realm...................................