macOS Remote Disc: Sharing an Optical Drive, and What Replaced It
Remote Disc lets a Mac without an optical drive use the CD or DVD drive in another computer over the local network. Apple introduced it when the MacBook Air shipped without a drive, and it remains in macOS. On the A+ exam it is a named macOS feature, and the more useful knowledge is what it cannot do — because that is where the support calls come from. How it works On the machine with the drive, sharing is enabled in Sharing preferences — DVD or CD Sharing on a Mac, or a small Apple-supplied utility on Windows. The client Mac then shows Remote Disc in the Finder sidebar under Locations, and an inserted disc appears there as though it were local. Both machines must be on the same local network. Discovery uses Bonjour, Apple's zero-configuration service discovery over multicast DNS, which means it works without any configuration on a flat network and stops working the moment the two machines are on different subnets. An option exists to prompt the sharing machine's user b...