system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5 how does the eco setting on a washing machine save energy and water by washing the laundry for *longer*?

Edit: Thank you to everyone that replied!
gpt
The motor of the washing machine uses very little power when it's just moving the clothes around. It's a bit more during the spin cycle, but that doesn't last very long.

The vast majority of the power is used to heat the water, so if you can use a lower temperature and/or less water and instead just have the motor do its thing for a longer time, you use less energy (and water) overall.