Why Do Operating Systems Exist?
Imagine if every application you used had to know exactly how to communicate with your specific keyboard, your specific display, your specific storage device. Every program would need code for thousands of different hardware configurations. Updates would break constantly. It would be chaos.
This is the problem operating systems solve.
The Middle Layer
An operating system (OS) sits between hardware and software. It handles all the messy details of communicating with physical components, then presents a clean, consistent interface to applications. Programs don't need to know whether you have an Intel or AMD processor, an SSD or hard drive, a wired or wireless keyboard. They just ask the OS to "save this file" or "display this window," and the OS figures out the hardware specifics.
Think of the OS as hotel management. Guests (applications) don't need to know how the plumbing works, where the electricity comes from, or how housekeeping is scheduled. They just request services, and management coordinates everything behind the scenes.
Coordination and Protection
Modern computers run many programs simultaneously. Your web browser, music player, and text editor might all be running at once. The OS coordinates this, deciding which program gets CPU time, allocating memory to each, and ensuring they don't interfere with each other.
This protection is crucial. Without it, a buggy program could crash your entire computer by overwriting another program's memory. The OS keeps programs isolated, like separate apartments in a building. Each has its own space, and problems in one don't automatically spread to others.
Standardized Services
Operating systems provide standardized services that all applications can rely on: file storage, network access, user input, graphics display, and more. This standardization is why you can install software written by developers who have never seen your specific computer. They wrote their code to work with the OS, and the OS handles your particular hardware.
Resource Management
The OS manages limited resources — CPU time, memory, storage space, network bandwidth. It decides how to divide these resources among competing programs, balancing fairness with priority. This resource management happens constantly, invisibly, making your computer usable.