What is the main difference between system software and application software?
System software (like the operating system) manages and runs the computer itself, while application software performs specific tasks for the user, such as word processing or browsing the web.
What are the three main purposes of an operating system?
1) Allocate resources between applications (CPU time, memory). 2) Provide an interface that abstracts hardware details for programmers. 3) Provide common services like network and disk access.
What is the kernel in an operating system?
The kernel is the core part of the operating system that is always running and manages the computer's resources. It handles low-level tasks like memory and process management.
What is a system call?
A system call is a request made by an application program to the operating system to perform a privileged operation, such as reading a file or sending network data.
Name three examples of mobile operating systems.
Android, iOS, and iPadOS are examples of mobile operating systems for smartphones and tablets.
Name three examples of desktop operating systems.
Microsoft Windows, macOS, and Linux (e.g., Ubuntu) are examples of desktop operating systems.
What is an embedded operating system? Give an example.
An embedded operating system is designed for embedded systems (like appliances or IoT devices) and does not load user-installed software. Examples include Embedded Linux, QNX, VxWorks, RIOT, and TinyOS.
What is a real-time operating system (RTOS)?
A real-time operating system is designed to process data and respond within a guaranteed time constraint, often used in critical systems like medical devices or industrial control.
What is the role of the operating system in managing hardware?
The OS acts as an intermediary between programs and hardware, handling input/output, memory allocation, and scheduling tasks to use the CPU efficiently.
What is time-sharing in an operating system?
Time-sharing is a technique where the OS schedules tasks so that multiple users or applications can share the computer's resources efficiently, giving each a slice of CPU time.
What is virtual memory?
Virtual memory is a technique that uses part of the hard drive as an extension of RAM, giving programs the illusion of more memory than physically available.
What is a utility program? Give an example.
A utility program is a system software that performs maintenance or support tasks, such as disk cleanup, antivirus scanning, or file compression. Examples include Windows Disk Cleanup and antivirus software.
What is the difference between a distributed system and a multicomputer?
A distributed system is a group of distinct, networked computers that may be geographically dispersed, each with its own OS. A multicomputer (or cluster) has multiple CPUs with separate memory, usually in one location, and is common in cloud computing.
What is middleware?
Middleware is an additional software layer between the operating system and applications that helps different applications or systems communicate and share data, often used in distributed systems.
What is a live CD or LiveUSB?
A live CD or LiveUSB is an operating system that can run directly from a CD or USB stick without being installed on the computer's hard drive.
What does OEM-installation mean?
OEM-installation means the operating system comes pre-installed on a computer when it is purchased, such as Windows on many laptops.
Why do operating systems isolate applications from each other?
To protect applications from errors or security vulnerabilities in other applications, ensuring that one program cannot crash or compromise another.
What is the most popular operating system as of November 2025?
Android, with a 38% market share, followed by Microsoft Windows at 33%.
What is a special-purpose operating system?
An operating system designed for a specific function or device, such as embedded systems, real-time systems, or security-focused systems.
What is a multicomputer operating system?
An operating system designed for a multicomputer or cluster, where multiple CPUs each have their own memory and communicate via messages. It often supports remote procedure calls or distributed shared memory.
What is a remote procedure call (RPC)?
A remote procedure call is a technique where a program can call a procedure on another CPU or computer over a network, as if it were a local call.
What is distributed shared memory?
Distributed shared memory is a technique where the operating system uses virtualization to give multiple computers the illusion of a shared memory space, even though it does not physically exist.
What is the smallest type of embedded operating system?
The smallest embedded operating systems are for smart cards, running in less than 10 kilobytes.