Computer Applications and Office Tools

Operating System

An operating system (OS) is the system software that acts as an interface between the user and the computer hardware. It manages all hardware and software resources of a computer system and provides an environment in which application programs run. Examples: Windows, Linux, macOS, Android.

Role of Operating System as a Resource Manager

The OS acts as a resource manager because the resources of a computer (CPU, memory, I/O devices, files) are limited and many programs compete for them. The OS allocates, controls and monitors these resources so that they are used efficiently and fairly. Its main roles are:

1. Processor (CPU) Management — The OS decides which process gets the CPU and for how long, using scheduling techniques (FCFS, Round Robin, Priority). This keeps the CPU busy and gives each process a fair share of processing time.

2. Memory Management — It allocates memory to programs when needed and reclaims it when the program ends. It keeps track of used and free memory, and uses techniques like paging and virtual memory to run programs larger than physical memory.

3. Device (I/O) Management — It controls input/output devices such as keyboard, printer and disk through device drivers. It allocates devices to processes, handles interrupts and buffers data so that slow devices do not hold up the CPU.

4. File Management — It creates, stores, retrieves and deletes files and directories. It keeps track of file locations on the disk, controls access permissions and protects files from unauthorized use.

5. Process Management — It creates, schedules, suspends and terminates processes, and allows processes to communicate and synchronize with each other.

6. Security and Protection — It prevents one program or user from interfering with another by controlling access to resources through passwords and access rights.

In short, the OS acts as an intermediary that allocates limited hardware resources among competing programs, monitors their use, and resolves conflicts — which is why it is called the resource manager of a computer system.