System software is the layer of software that manages a computer's hardware and provides the basic platform on which application software runs. Its major function is controlling the computer system, coordinating the processor, memory, storage, and peripheral devices so that everything works together correctly.
Examples of system software include the operating system, device drivers, and utility programs, all of which exist primarily to manage hardware resources, schedule tasks, and keep the system running, rather than to perform a specific end-user task like word processing or accounting.
Making navigation easier and giving utility functions are things certain parts of system software may also assist with, but they describe secondary conveniences, not the fundamental, defining role of system software, which is to control and manage the computer system itself so that everything else can run on top of it.
Exam tip: separate system software, which manages the machine itself, from application software, which performs specific user tasks, the major function of system software is always about controlling and coordinating the underlying computer system.