Apart from the default startup disk, Mac computers can be set to start up from a different disk like an external drive, network volume, or a USB flash drive. This article explains the process for ...

Disk Utility is Apple's go-to macOS app for finding and repairing common disk errors, but if it's your Mac's internal disk that's the problem, then your Mac might not even start up into macOS.

If your Mac has multiple bootable disks—via either a partitioned internal disk or external FireWire drives—you’re probably very familiar with the Startup Disk System Preferences panel. As you’d guess ...