a drain more than likely goes to a sewer.
OF COURSE
A snake won't go down a bathtub drain because the drain is too small for its body to fit through.
The evaporator drain allows condensation from the ac unit to drain. When the drain clogs up water will go into the passenger floor instead.
A snake won't go down the shower drain because its body is too large to fit through the small openings in the drain.
It is the drain.
Drain cleaner pollutes the environment after it is poured down the drain. You should use green cleaners.
The sewer is where all detergent goes when it goes down the drain. Any type of liquids which go down a drain will go into the municipal sewer lines and may end up in treatment plant.
All of them?
The sewer
the sewer is where things that you flush or put down the drain go, a drain is the opening is a sink or shower that sends things to the sewer
Drain cleaner or a snake. If you use a snake, take the overflow plate off on the side of the tub above the drain and go down from there. That saves making the sharp bend if you go through the drain itself. It may be hair wrapped around the drain shut off which will come out when you remove it from the overflow tube.
How do you replace the trunk drain hoses on a 1965 thunderbird.