A p-trap pipe was designed to prevent sewer gas from backing into homes. It is called a p-trap because it is shaped like someone flipped the letter P and laid it down. Its design creates an airtight seal by holding enough water in the curved section.
P-trap refers to the water seal at the bottom of the toilet that stops sewer gases and smells escaping into your bathroom. The set out of a toilet outlet refers to the outlet drainage point location.
A P-trap toilet has a trap that is shaped like a “P”. It is a curved pipe that is designed to hold water and create a barrier between the toilet bowl and the waste pipe. The water in the P-trap prevents sewer gases from entering the room, as the gases are unable to flow back up through the trap. P-trap toilets are more common in modern construction and renovations, as they are more effective in preventing odors and are easier to maintain.