Not only is it faster to copy data such as setup files from a USB drive, but during usage the access times are also significantly faster. There are reasons why you would, however, choose a USB device over a DVD disc, and bootable software is definitely one of them. USB drives tend to be higher in capacity than disc media, but since they are more expensive, they cannot (yet) really be used as a replacement. The USB flash drive has replaced the floppy disk drive as the best storage medium for transferring files, but it also has its uses as a replacement for CDs and DVDs.
