System software is software on a computer that is designed to control and work with computer hardware. The two main types of system software are the operating system and the software installed with the operating system, often called utility software. The operating system and utility software typically depend on each other to function properly.

Exampls : … Read more

Basically it is software aimed to tweak/tune/manage your Operating System in many ways. It can be something related to the Registry, or the Drivers or the Security, the maintenance of a system... It's a very general definition.