"An operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs."
The study of the design and management of computer operating systems, including memory management, process management, and file systems.
Process Management: The management of processes within an operating system. This includes scheduling, memory allocation, process synchronization, and inter-process communication.
Memory Management: The allocation and de-allocation of memory within an operating system. This includes virtual memory, paging, swapping, and memory protection.
File System Management: The management of files and directories within an operating system. This includes file naming, storage allocation, file access, and file sharing.
Device Management: The management of device drivers within an operating system. This includes device I/O, interrupt handling, device discovery, and drivers.
Networking: The management of network protocols within an operating system. This includes network stacks, sockets, IP addressing, and routing.
Security: The management of security within an operating system. This includes authentication, access control, encryption, and firewalls.
Kernel Architecture: The architecture of the kernel within an operating system. This includes system calls, kernel space, user space, and interrupts.
Virtualization: The management of virtualization within an operating system. This includes virtual machines, hypervisors, and containers.
"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."