S, M, L on Washing Machine

What is (are?) the difference(s) between the small, medium and large settings on a washing machine? Amount of water used? Duration of cycle?

What are the possible consequences of washing a “large” load on a “small” cycle and conversely?

TIA for answers and/or comments.

The water level, or the amount of water that is put into the machine.

If you fill up the basket with laundry and choose “small” your laundry will not get clean and will probably end up soapy because there is more laundry than water.

If you put a few pairs of pants in the basket and choose large, you’re just wasting water.

My mom told me that if you choose “small,” you should also choose “gentle cycle” or you will beat your clothes to death.

My grand mother said to or it would beat the fire out of them.

S, M, L is water level

Heavy, Normal, Light is usually cycle time

Normal, Permanent Press, Gentle is agitation speed.