What is a brine shrimp cyst?

It's when a Brine Shrimp is held in a state of suspended-animation. That's what sea monkeys are. They're just Brine Shrimp cysts. The shrimp are still alive, just in.... Hibernation is the best way I can describe it. When they hit the water and receive certain activators, the shrimp come out of their cysts, and begin life (Again).