The expression “ça marche” is often used in everyday situations when someone agrees with what has just been said.
Literal translation: That walks
Actual meaning: Ok, that works!
– Tu peux venir à 6 heures ce soir. You can come at 6pm.
– Ok, ça marche ! Ok that works!
But you could also use it to talk about something that works well like a car or a computer etc…
– Est-ce que ta voiture marche bien? Is your car running well?
– Oui, elle marche très bien! Yes it is running very well!