Chapter 1 — Chapter 1 — Operating Systems: Structure and Services

An operating system (Windows, Linux, macOS, Android) is system software that manages hardware and software resources and provides services to programs. It is called the central controller because it coordinates CPU, memory, storage and devices and decides which program uses what and when. It acts as a translator: user actions (clicks, commands) are converted into instructions the hardware understands, and results are returned to the user. Functions: process, memory, file, device and security management, user interface. In multi-user environments the OS gives each user an account, ensuring equal access and data privacy. Windows accounts are created via Settings → Accounts → Family & other users → Add account (or Control Panel → User Accounts).