The answer to 'difference between drain' is that drains and sewers are two distinct components of a home's plumbing system, each serving a specific purpose. Drains are the pipes that carry wastewater from sinks, showers, tubs, and other fixtures to the main sewer line, while the sewer line is the larger pipe that carries all the wastewater from the home to the municipal sewer system or a septic tank.
Drains are typically smaller in diameter, ranging from 1.5 to 4 inches, and are designed to handle the flow of water and waste from individual fixtures. Sewers, on the other hand, are larger pipes, usually 4 inches or more in diameter, that collect and transport the combined wastewater from all the drains in the home. Sewers are responsible for carrying the waste to the main public sewer system or a septic tank, where it can be properly treated and disposed of.