If you're on #macOS and you want to take a DVD with you without taking your DVD _drive_ with you, you can install dvdbackup and libdvdcss from Homebrew, insert and unmount (but don't eject, i.e. `diskutil unmount`) your DVD, then run `dvdbackup -Mvpi /dev/disk3` (where `disk3` is the device your DVD is mounted to, cf. `diskutil list`)