(a) The operating system of modern computers has progressed from a command-driven system to a graphical user interface (GUI). Describe three advantages to the user of using a graphical user interface rather than a command-driven system.

(b) 'The operating system is the software heart to the machine.' Give a detailed explanation of what the operating system of a modern PC does.

(c) Define the term 'operating environment'.

(d) Define the term 'user interface', giving examples.

(a) Three advantages of using a graphical user interface rather than a command-driven system are:

1. GUIs are very easy to learn and use making them extremely user friendly.
2. User does not need prior computer skills or knowledge to perform operations through GUI.
3. GUIs are visually appealing and provide immediate feedback, helping users understand the impact of their interactions.

(b) The operating system (OS) of a modern PC is a fundamental software component that acts as the bridge between the hardware and the user. It plays a crucial role in managing and coordinating all the resources and functionalities of the computer system. It manages hardware resources, runs and coordinates software applications, provides user interfaces, ensures system security, and enables networking capabilities. The main functions of the operating system of a modern PC are:

1. Processor Management — The Processor management function of an OS allocates an important computer resource CPU to various running programs or applications. This function of an OS prepares, schedules, controls, and monitors jobs or processes submitted for execution to ensure the most efficient processing.
2. Memory Management — The memory management function allocates memory to the running processes and de-allocates memory from the process, when it gets completed.
3. Device Management — This function of an operating system is responsible for proper handling of input and output devices. This function ensures smooth reading of data from the input devices and sending the data to correct output devices.
4. File Management — An operating system governs the permanent storage and retrieval of data from/to an external storage device.
5. User Interface — The OS establishes a standard means of communication between users and their computer systems. It does this by providing a user interface and a standard set of commands that control the hardware.

(c) Operating environment refers to the specific conditions and factors in which a computer system operates. It includes things like the type of computer, operating system, network setup, and user interactions that can affect how the software functions. Understanding the operating environment helps ensure that the software works well and meets its requirements in that particular context.

(d) A user interface (UI) is a means through which a user interacts with a computer system. It serves as a bridge between the user and the underlying technology, allowing users to communicate their intentions and receive feedback from the system in a human-readable and intuitive way.
Some examples of user interfaces are:

1. Command-Line Interface (CLI) — Unix, DOS.
2. Graphical User Interface (GUI) — Windows, MAC OS
3. Touchscreen Interface — Android, iOS.