System software performs tasks like transferring data from memory to disk, or rendering text onto a display device. Specific kinds of system software include loading programs, Operating systems, device drivers, programming tools, compilers, assemblers, linkers, and utility software.
Software libraries that perform generic functions also tend to be regarded as system software, although the dividing line is fuzzy; while a C runtime library is generally agreed to be part of the system, an OpenGL or database library is less obviously so.
System Software can be classified as operating system and language processors. Operating system creates an interface between user and the system hardware. Language processors are those which help to convert computer language (Assembly and high level Languages) to machine level language. The example of language processors are assemblers, Compilers and interpreters.