The three main components of an operating system are:
1. manage the computer's resources (this includes the central processing unit, memory, printers, and disk drives).
2. establish a user interface (this is where the human interacts with a computer, website or application. the UI, also known as user interface, is to make the user's experience easy and intuitive).
3. execute and provide services for applications software (this is the interface between the application program and the hardware, which gets carried out from OS).