Storage management software is used in everything from desktop computers to mainframes and includes products that work on limited or a single set of devices, as well as those that work universally and support a heterogeneous device set. Storage management software also makes use of hierarchical storage management (HSM) systems, which back up data from the main storage into slower, less expensive storage devices. The market to which this software belongs is divided into seven segments. Storage management software is the sum of all these segments, and represents all the tools that are needed to manage the performance, capacity and availability of the data stored on disks or any storage device attached to the system.