Operating Systems: Types, Functions and Examples

An operating system is the core system software that manages computer hardware and software resources while providing common services for programs. It acts as an interface between the user and the machine, making it possible to run applications efficiently and securely.

Core Functions of an Operating System

An operating system performs several essential tasks to ensure smooth execution of programs and proper use of system resources. These functions are central to how a computer works.

• Process Management: The operating system creates, schedules, suspends, and terminates processes. It also handles process synchronization and inter-process communication.
• CPU Scheduling: It allocates processor time among different tasks using scheduling algorithms, helping multiple programs run efficiently.
• Memory Management: It tracks every byte of primary memory, manages allocation and deallocation, and ensures that programs do not interfere with one another’s memory space.
• Virtual Memory: It coordinates the movement of data between main memory and secondary storage so that larger programs can run even when physical memory is limited.
• File System Management: It organizes data into files and directories, controls access permissions, and manages storage allocation on devices such as hard drives and solid-state drives.
• Device Management: It manages communication with hardware through drivers and handles devices such as printers, keyboards, and displays.
• Input/Output Control: It queues input and output requests to improve device utilization and system performance.

Types of Operating Systems

Operating systems are classified according to architecture, capability, and the environment in which they operate. Each type is designed for a specific kind of workload or device.

Major Examples and Architectures

Different operating systems are built for different hardware architectures and user needs. Some are proprietary, while others are open-source and widely adapted.

• Microsoft Windows: A proprietary operating system family developed by Microsoft with a dominant market share in personal computing.
• Linux: A family of open-source Unix-like operating systems based on the Linux kernel, widely used in servers and supercomputers.
• macOS: The proprietary operating system developed by Apple for its Mac line of computers, built on the Unix architecture.
• Android: A mobile operating system based on a modified version of the Linux kernel, developed primarily by Google for touchscreen devices.
• iOS: A mobile operating system created and developed by Apple Inc. exclusively for its hardware.

Key Components and Important Facts

The operating system relies on a central core known as the kernel. It controls system operations and has complete authority over the hardware and essential processes.

• Kernel: The core component of an operating system that has complete control over everything in the system.
• System Software: An operating system is system software, not application software, because it manages the computer environment rather than performing a single user task.
• Intermediary Role: It works between hardware and the end user, translating user requests into machine-level operations.
• Resource Management: It allocates and controls hardware, memory, files, and devices so that multiple programs can run together.
• Security Control: Through permissions and access control, it helps protect files and system resources.

Historical and Exam-Relevant Facts

• First Operating System: The first operating system was developed in the mid-1950s for the IBM 704 computer and was known as GM-NAA I/O.
• Unix: Unix was developed in 1969 at AT&T Bell Labs by Ken Thompson and Dennis Ritchie.
• Linux Kernel: The Linux kernel was released in 1991 by Linus Torvalds.
• Real-Time Use: Real-time operating systems are widely used in air traffic control systems, industrial robots, and medical equipment.

Key Prelims Takeaways

• Operating system: System software that manages hardware, software resources, and common program services.
• Interface role: It acts as the bridge between the user and computer hardware.
• Process management: Includes creation, scheduling, synchronization, and termination of processes.
• Memory management: Handles allocation, deallocation, and virtual memory.
• File system management: Organizes files, directories, permissions, and storage allocation.
• Device management: Uses drivers to manage devices and queue I/O requests.
• High-yield examples: Windows, Linux, macOS, Android, and iOS are key operating system examples.