system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the difference between poison, venom, and toxin?
gpt
*Toxins* are substances which have a profound negative effect on the body, which may be produced by the body or from an outside source. 

*Poisons* are toxins which are ingested, and often are produced by plants. Potassium cyanide is such a poison. Lead and arsenic are examples of inorganic poisons (they have no carbon).

*Venoms* are organic toxins which are injected, and usually are produced by animals.