Definition: A rackbone is a type of data compression technique used in computer storage systems. It compresses large files by using a set of "racks" to store them, and then re-compresses each individual file within its own rack. This approach allows for faster access to data since the data is stored only once in memory. In summary, a rackbone is a method used by computer storage systems to compress large files into smaller pieces, which can be accessed more quickly.