A computer’s operating system manages a system’s hardware and software resources, storage, memory and processes. As a resource manager, it handles and runs the computer's memory, processor, input and output devices, and disk space.
Because programs and processes compete for the central processing unit and demand resources such as memory and storage, the operating system ensures that each process or program receives the necessary resources it requires. It also identifies when the central processing unit executes a process or action.
An operating system also controls how the computer stores data and the access and creation of files by users. It is also responsible for allocating and de-allocating memory to processes.