What Is an Operating System? โ 10 Minutes of Operating Systems, Day 1
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Before We Begin ๐
The smartphones, laptops, and tablets we use all have an operating system installed. But what exactly is an operating system, and what does it do?
In this post, we will gradually explore what operating systems are, why they matter, and their core functions. Starting with the basics, we will cover resource management, security, virtualization, and other topics using simple examples.
Definition and Roles of an Operating System ๐
An operating system (OS) is software that
acts as a bridge between computer hardware and users
. Simply put, when you want to run a program or save a file, the operating system is the system that actually handles it.
Its main roles include:- Managing program execution: coordinating multiple programs running at once to prevent conflicts.
- Managing resources: efficiently allocating resources such as the CPU, memory, storage, and input/output devices.
- Providing a user interface: letting users interact with the system through a command-line interface (CLI) or graphical user interface (GUI).
For example, when you open Word, listen to music, and browse the web simultaneously on Windows, the operating system coordinates all these activities.
Components and Structure of a Computer System ๐
A computer system can be divided into three main parts:
- Hardware: the CPU, memory, disks, input/output devices, and so on.
- Operating system: software that controls hardware and mediates user requests.
- Application programs: programs users interact with directly, such as web browsers, games, and text editors.
The operating system mediates between these components, helping each work smoothly.
A computer system has the following layered structure:
- User - Application programs - Operating system - Hardware
This structure lets the operating system hide hardware complexity, making the system easier for users and developers to work with.
How Operating Systems Work and Manage Resources ๐
An operating system is like a manager overseeing all system resources. It includes a
scheduler
that decides the order in which running programs use the CPU, a memory manager
that allocates memory, and a file system manager
that reads and stores files.
The resources it manages include:- CPU time
- Main memory (RAM)
- Secondary storage (HDDs and SSDs)
- Input/output devices (monitors, keyboards, printers, and so on)
By managing these resources efficiently, it improves performance and helps the system operate reliably without conflicts or errors.
Security, Protection, Virtualization, and Distributed Systems ๐
Operating systems do more than manage resources. They also provide security and protection and are designed to adapt to various system environments.
- Security: protects the system from external intrusions and malicious programs. Examples include user authentication, encryption, and access control.
- Protection: prevents internal users or programs from accidentally accessing resources belonging to other programs.
- Virtualization: allows multiple operating systems or environments to run virtually on one hardware system. For example, it lets you run Windows and Linux simultaneously on one computer.
- Distributed systems: technology that connects multiple computers so that they work as one system. Large server environments at companies such as Google and Amazon are examples.
Kernels, Computing Environments, and Open-Source Operating Systems ๐
- Kernel: the core of an operating system, responsible for resource management, handling system calls, and other essential tasks. It is like the heart of the operating system.
- Computing environments: operating systems may work differently across desktop, mobile, cloud, IoT, and other environments.
- Open-source operating systems: operating systems that anyone can use and modify for free. Linux is a leading example, widely used for learning and running servers.
Summary ๐
Using simple examples, we have explored what an operating system is, what it does, and why it matters.
Beyond simply making a computer run, an operating system efficiently manages resources and connects users with hardware. In the next post, we will take a closer look at how operating systems are structured and designed.
References ๐
- Operating System Concepts, 10th Edition โ Abraham Silberschatz et al.
- https://en.wikipedia.org/wiki/Operating_systemโ