There are multiple status effect that can be inflict to or by your Pokemon.
Sleep: Causes your Pokemon to fall Unconscious for several turns or until healed.
Poison: Your Pokemon becomes poisoned, taking damage over time for several turns or until healed.
Confusion: Your Pokemon becomes confused, causing them to move in random directions, and may cause their skills to fail. Confusion lasts for several turns, or until healed.
Paralyze: When a Pokemon becomes paralyzed, they will may become unable to move, attack, or use abilities. Paralyze lasts until the Pokemon is cured of it, or you visit a pokemon center.