The opioid analgesic ingredient in Vicodin is Hydrocodone.
Vicodin is a brand name of a medication containing both hydrocodone and acetaminophen.
Hydrocodone is an ingredient in Vicodin which is a "trademarked" name.
Vicodin has Hydrocodone in it. Vicodin is a combination of Hydrocodone and Acetaminophen so no Hydrocodone is only one of the two drugs that is in Vicodin.