В чем разница между waschen и spülen ?Пожалуйста, приведите примеры.

Waschen means to clean your body, cloth or a car etc. using water and or soap etc.

Spülen is the action of letting water run/flow over or through something thereby cleaning it (you dont nessersarly do the cleaning yourself with your hands but the water does it).

In the case of "Geschirr spülen " this means let water run over the dishes and clean them using a sponge or similar tools.

but you can also say
Das Klo spülen.
This just means.
Flush the toilen.

Or
Die Haare waschen.
(this is the whole procedure, making your hair wet, getting shampoo into your hair, and then cleaning it of)
To wash your hair.

Die Haare spülen.
(this just means to let water flow through your hair to get the shampoo out)
Rinse your hair.