What an operating system actually does
An operating system coordinates hardware and gives applications common services. It schedules CPU time, manages memory, stores files, controls devices and enforces permissions. This lets a browser use…
An operating system coordinates hardware and gives applications common services. It schedules CPU time, manages memory, stores files, controls devices and enforces permissions. This lets a browser use a network card without knowing every electrical detail of the hardware.
How it works
The operating system is also a security boundary. User accounts, process permissions and updates reduce the impact of mistakes and vulnerabilities. When an app asks for a permission, it is asking the operating system to allow access to a resource.
Practical takeaways
Keep the system updated, use a standard account for daily work and remove applications you no longer need. Backups should be tested outside the operating system so a corrupted installation cannot destroy every copy.
Windows, macOS, Linux, Android and iOS make different trade-offs, but all perform the same broad coordination role.
In short: An operating system is the layer that turns hardware into a usable platform while managing resources and permissions.