An operating system (OS) manages a computer's hardware and provides the environment in which applications run. An application performs a specific task for the user, while the operating system coordinates the computer's underlying resources.
This distinction is part of 3.3 Computers, which is shared by SL and HL Digital Society students.
When a computer starts, the operating system is loaded and takes control of resources such as the processor, memory, storage and connected devices. It performs essential functions including scheduling processes, organizing files, allocating memory, managing user accounts and controlling access to hardware.
An application is software designed for a particular user-focused purpose, such as editing a document, browsing web content or playing media. Instead of controlling hardware directly, it normally requests operating-system services through an application programming interface (API) or system calls. For example, when an application saves a file, the operating system manages how and where the data is written to storage.
| Feature | Operating system | Application |
|---|---|---|
| Main purpose | Manages hardware and software resources | Performs a specific user task |
| Relationship to hardware | Controls and coordinates hardware | Usually accesses hardware through the OS |
| When it runs | Starts during boot and normally runs continuously | Runs when opened or needed |
| Effect of failure | May disrupt the entire computer and its applications | Usually affects only that application |
| Software category | System software | Application software |
A common misconception is that any program used on a computer is an application. The operating system is also software, but it is classified as system software because it supports the operation of the computer and other software.