system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is water managed and supplied in Trains ?

You can use well explained technical terms and please talk about normal trains that are used for daily commute not the rather hi-tech ones !
gpt
Pretty much like in an RV.  There are tanks to hold clean water, typically refilled with a hose at the ends of the line.  These are usually mounted above the sinks and toilets, so gravity delivers the water.

The drains all connect to storage tanks under the cars, which are pumped out at the end of the line.