Features of a typical operating system

An operating system (OS) is system software that manages the hardware and gives a base for application programs. The key features of a typical OS are as follows.

1. Process management: creates, schedules and ends processes; provides multitasking by sharing the CPU among many processes (scheduling algorithms), and handles synchronisation and communication between processes.
2. Memory management: allocates and frees main memory, keeps track of which parts are in use, protects one program from another, and provides virtual memory (paging, segmentation) so that programs larger than RAM can run.
3. File management: organises data in files and directories, and handles creating, reading, writing, deleting, naming, access rights and storage allocation on disks.
4. Device (I/O) management: controls peripherals through device drivers, buffering, caching and spooling, and gives a uniform interface to the programs.
5. Security and protection: user authentication (passwords), access control and protection of data and programs from unauthorised use.
6. User interface: a command line interface (shell) or a graphical user interface (GUI) to let the user work with the computer.
7. Resource allocation and accounting: distributes CPU, memory and I/O devices fairly and records their usage.
8. Error detection and handling: detects hardware and program errors and takes proper action, to avoid system crash.
9. Networking: supports communication between computers and sharing of resources.
10. Interrupt and deadlock handling: services interrupts and deals with deadlocks.