Os Glossary

Browse 23 os terms defined in plain English, from the cultural dictionary of computing.

23 Os Terms

Capability
An unforgeable token or reference that grants the holder permission to perform a specific operation on a specific resource — a security model where possessing...
Configuration File
A Configuration File is a development concept used to shape how software is built, executed, or maintained in real systems. Developers rely on it to make code...
Context Switch
The process of saving one thread/process's state (registers, program counter, stack pointer) and loading another's so the CPU can switch between tasks. Costs...
Device Driver
A specialized program that acts as a translator between the operating system and a hardware device, abstracting the device's specific protocol behind a...
File Descriptor
A File Descriptor is a development concept used to shape how software is built, executed, or maintained in real systems. Developers rely on it to make code...
File Handle
A File Handle is a development concept used to shape how software is built, executed, or maintained in real systems. Developers rely on it to make code easier...
File Lock
A File Lock is a development concept used to shape how software is built, executed, or maintained in real systems. Developers rely on it to make code easier to...
File System
A File System is a development concept used to shape how software is built, executed, or maintained in real systems. Developers rely on it to make code easier...
File Watcher
A File Watcher is a development concept used to shape how software is built, executed, or maintained in real systems. Developers rely on it to make code easier...
Flat File
A Flat File is a development concept used to shape how software is built, executed, or maintained in real systems. Developers rely on it to make code easier to...
Interrupt
A signal to the processor that an event needs immediate attention, temporarily halting the current execution to run an interrupt handler. Hardware interrupts...
Interrupt Handler
A callback function registered with the kernel that executes immediately when a hardware or software interrupt fires, preempting the currently running code to...
Kernel
The core component of an operating system that manages hardware resources and provides services to user-space programs. The Linux kernel, Windows NT kernel,...
Page Fault
An interrupt triggered when a program accesses a virtual memory page that isn't currently mapped to physical RAM. Minor page faults load the page from the page...
Resource Limit
A cap imposed by the operating system, container runtime, or platform on how much of a given resource (CPU, memory, file descriptors, processes, network...
semaphore
A synchronization primitive that controls access to a shared resource through a counter, allowing a specified number of threads to access the resource...
Signal
An asynchronous notification sent to a process by the OS (e.g., SIGTERM, SIGKILL) to indicate an event, or in reactive programming, a primitive that holds a...
Swap
Disk space used as virtual memory when physical RAM is full. The OS 'swaps' memory pages to disk — functional but orders of magnitude slower. If your server is...
Synchronization Primitive
A low-level building block — such as a mutex, semaphore, spinlock, condition variable, or atomic operation — provided by the OS or language runtime to...
System Call
The interface between a user-space program and the operating system kernel. When a program needs OS services (file I/O, network, process creation, memory...
System Tray
A designated area of the desktop taskbar (notification area on Windows, menu bar on macOS) where background applications display persistent status icons and...
Task Scheduler
A system component that triggers jobs at specified times or intervals — at the OS level, this is cron on Unix or Task Scheduler on Windows; at the application...
Thread
The smallest unit of execution that an operating system can schedule. Threads within a process share memory space, enabling parallel execution but requiring...

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