"An operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs."
A software that manages computer hardware and provides common services for computer programs, including process scheduling, memory management, and file system.
Computer System Architecture: This topic covers the basic organization and components of a computer system, including the CPU, memory, input/output devices, and system buses.
Operating System Concepts: This topic covers the basic concepts and functions of operating systems, such as process management, memory management, file systems, and security.
Process Management: This topic covers the management of multiple processes within an operating system, including scheduling, synchronization, and communication between processes.
Memory Management: This topic covers the allocation and management of memory resources within an operating system, including virtual memory, paging, and segmentation.
File Systems: This topic covers the organization and management of file storage within an operating system, including access control, directory structures, and file attributes.
Input/Output Systems: This topic covers the management of input/output devices within an operating system, including device drivers and interrupt handling.
Interprocess Communication: This topic covers the various techniques used for communication and synchronization between processes within an operating system, including shared memory, message passing, and semaphores.
Security and Protection: This topic covers the techniques used for securing and protecting an operating system, including access control, authentication, and encryption.
Distributed Systems: This topic covers the design and implementation of operating systems for distributed computing environments, including network communication, distributed file systems, and distributed process management.
Real-time Systems: This topic covers the design and implementation of operating systems for real-time systems, including scheduling, response time analysis, and interrupt handling.
Multicore Systems: This topic covers the design and implementation of operating systems for multicore processors, including thread management, parallel processing, and synchronization.
System Performance: This topic covers techniques for monitoring and improving the performance of an operating system, including profiling, tuning, and benchmarking.
Embedded Systems: This topic covers the design and implementation of operating systems for embedded systems, including low-power and real-time requirements.
Debugging and Troubleshooting: This topic covers the techniques for debugging and troubleshooting problems within an operating system, including using diagnostic tools and analyzing system logs.
Single-user, single-tasking OS: An operating system that supports only one user working on one task at a time.
Single-user, multi-tasking OS: An operating system that allows a user to run multiple applications simultaneously, but only one user can be logged in at a time.
Multi-user, multi-tasking OS: An operating system that supports multiple users working on multiple tasks simultaneously.
Real-time OS: An operating system that is designed to execute real-time applications that process data as it comes in, without delay.
Network OS: An operating system that is optimized for managing network resources and providing network services.
Mobile OS: An operating system used in mobile devices like smartphones, tablets, and smartwatches.
Embedded OS: An operating system that is used in embedded systems, such as medical equipment, automotive systems, and consumer electronics.
Distributed OS: An operating system that spans multiple computers and networks, providing a unified computing environment.
UNIX and UNIX-based OS: An operating system that consists of a kernel, shell, and applications; popular in scientific, engineering, and academic environments and used as the basis for many other operating systems, like Linux.
Windows OS: A family of operating systems developed by Microsoft that runs on personal computers, servers, and mobile devices.
Linux OS: An open-source operating system based on the UNIX operating system and widely used in servers, supercomputers, and embedded systems.
MacOS: An operating system developed by Apple Inc. that is exclusively used in Apple’s hardware products.
Android OS: An open-source mobile operating system developed by Google that is used in smartphones, tablets, and other mobile devices.
iOS: A mobile operating system developed by Apple Inc. that runs exclusively on Apple’s hardware devices.
"Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, peripherals, and other resources."
"For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware."
"Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers."
"In the personal computer market, Microsoft Windows holds a dominant market share of around 75%."
"macOS by Apple Inc. is in second place with a market share of 15%."
"The varieties of Linux are collectively in third place with a market share of 3%."
"In the mobile sector (including smartphones and tablets), Android's share is 70.82% in the year 2020."
"According to third quarter 2016 data, Android's share on smartphones is dominant with 87.5 percent."
"Apple's iOS has a market share of 12.1 percent on smartphones."
"While other operating systems amount to just 0.3 percent."
"Linux distributions are dominant in the server and supercomputing sectors."
"Yes, other specialized classes of operating systems (special-purpose operating systems), such as embedded and real-time systems, exist for many applications."
"Yes, security-focused operating systems also exist."
"Some operating systems have low system requirements (e.g. light-weight Linux distribution). Others may have higher system requirements."
"Some operating systems require installation or may come pre-installed with purchased computers (OEM-installation), whereas others may run directly from media (i.e. live CD) or flash memory (i.e. USB stick)."
"An operating system (OS)... provides common services for computer programs."
"Time-sharing operating systems... may also include accounting software for cost allocation of processor time, mass storage, peripherals, and other resources."
"For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware."
"Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers."