What are Rogue poisons and how do I use them?

Poisons are a vital part of the rogue's arsenal. As a rogue gains levels, they can complete quests which will grant them the skill to use poinsons purchased from NPC and apply them to their weapons. Some poisons add damage, some slow your enemy's movement speed, and some slow an enemy's casting speed, or reduce the effectiveness of healing spells cast on your target.