D2D may refer to any of the following:
1. Short for disk-to-disk, D2D is a backup solution that copies data from one hard drive to another hard drive. For example, D2D can be from the primary hard drive in the computer to another internal or external hard drive connected to the same computer.
2. D2D or disk-to-disk is also the name of the hidden partition found on Acer computers, used to restore Acer computers back to their factory settings. See the hidden partition definition for further information.