You have a plumbing project on the go, and someone asks you “Where’s the Vent?“, or tells you, “that fixture is S-trapped“. What does this mean? What is a vent and why do you need one? Everyone knows that every toilet, bathtub, sink, shower, etc. will have a drain to carry the water away to sewage treatment, or your septic. But not everyone knows that they ALL also need to be vented.