Ça marche pronounced 'sa marsh' literally means 'that runs' or 'that works'. You can use it literally to talk about whether something works, eg your car, watch or your bank card's contactless payment ...

You will hear it a lot in conversation and also see it if you're in text/chat groups with French friends eg 19h au resto ? Oui, ça marche - this signals agreement that you're meeting at the restaurant ...