Explanation:

An 'Operating System' (OS) is a collection of software that manages computer hardware and software resources and provides common services for computer programs. It acts as an intermediary between the user and the computer hardware, controlling how the system runs and processes information, including memory management, process scheduling, and file system management. A 'Compiler' translates high-level programming code into machine code. A 'Linker' combines object files and libraries into an executable program. An 'Assembler' translates assembly language code into machine code. These three are programming tools, not the central system manager like an OS.