I need to buy a backup for the new desktop - do these new mac’s have some special requirements for external hard drives? I ask because my mom got a new laptop as well and she was reading about some adapter she has to get when she buys a backup. Your expertise is appreciated!
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No special requirement really. You can use any hard drive with a USB to USBC adapter. You can, of course, just buy a USBC hard drive but there’s really no need to spend extra money. Since this particular drive would just be for backup, performance gains using USBC would not be noticeable.