Protoss:
From Auir to the Gods!
The Protoss are the race with the highest intelligence. They have researched technology which gives them a technological advantage over Terrans and Zerg. The Protoss were created by the Xel'Naga (a very very highly advanced race), and flourished for centuries... The Xel'Naga decided to live on However the Protoss slowly got tired of the Xel'Naga and eventually turned on them, killing many Xel'Naga. The Xel'Naga retreated into broad space and went on to create the Zerg. The Protoss were given the gift of strong psionic powers (psychic mixed with a little esp). Their psionic abilities allow the Protoss to communicate without talking and share ideas. With these divine powers the Protoss can control other creatures minds, and their psionic options increase when they are with more Protoss units.

History:
After decimating the Xel'Naga, the Protoss divided into several warring families. After several years, a wise combatant, Adun, developed a code of laws incorporating religion and a social structure. Adun called these rules "Khala." The social system that developed out of the Khala was Khalai: The artisans and inventors, Templar: warriors and explorers, and Judicator: administrators and leaders. With this order in place the consul commands all military affairs and deduces fixes for social problems.

Zerg:
Death is no barrier.
The Xel'Naga, upset and in pieces because of the Protoss revolution, decided to create a less intelligent race, for safekeeping. The Zerg was their creation, a race resembling insects which evolve their form and assimilates other races. Each Zerg also has a mental connection to the other Zerg. The Xel'Naga again decided to live among their creation, however they underestimated the Zerg's intelligence and power. Soon the Zerg,angered by the Xel'Naga's impudent behavior and commands, successfully launched a surprise attack. The Xel'Naga were utterly defeated (for the second time) and the Zerg learned the Xel'Naga's technology. The Zerg anatomy is interestingly unique. They are laid as larvae and grow and transform inside their "egg" to different beings. They have one claw on each arm and a hunch back. Without metal's the Zerg have a very strong exoskeleton.