A reboot turns off all processes on your PC momentarily and powers it on again, whereas a shutdown command will switch off the PC completely until you press the power button again. If you plan on not using your machine for an extended period, consider shutting it down. But, if you quickly need to get back to work, and use your PC regularly, there’s no real need to shut it down. Regardless, it’s recommended you perform a reboot every two to three days, as it gets rid of temp files and other cache files that take up space on your computer.