Question about cloud mining

Hey y’all, I’m pretty new to cryptos and I started using genesisminingbot to give it a shot, but I don’t understand something. The mining has begun, but they say « Your mining process is running in the background and will continue even if your device is turned off. » So if they don’t use my time or my device’s composants, what exactly are they paying me for? Also, do y’all recommend cloud mining? What has been your experience with it? Do you know good sites to do so other than genesis? Thanks for reading me !