Operating Systems - Vocabulary Flashcards

Vocabulary flashcards covering key OS concepts from the notes.

Operating System (OS)

A program that acts as an intermediary between a user and the computer hardware, providing an environment in which programs can be executed.

Purpose of an Operating System

To provide an environment in which a user can execute programs.

Primary goal of an OS

Make the computer system convenient to use.

Secondary goal of an OS

Make the computer system efficient to use.

Hardware

Provides basic computing resources such as the CPU, memory, and I/O devices.

Applications programs

Define how system resources are used to solve computing problems (compilers, databases, games, business programs).

Users

People, machines, or other computers that use the system.

Extended machine

OS concept where the OS provides a hardware abstraction to increase portability and protection and to simplify programming.

Abstract machine

The hardware independent interface provided by the OS to programs.

Hardware abstraction

A layer that hides hardware differences to provide a uniform interface to software.

Portability

The ability to run software on different hardware with minimal changes.

Protection

Safety from faults and interference; isolation among processes in a multi-user system.

Resource manager

OS function that coordinates limited resources (memory, disk, network), handles conflicts, and aims for fair and efficient access.

Memory management

Managing memory allocation, deallocation, protection, and sharing among processes.

IO management

Managing input/output devices and operations.

CPU scheduling

Deciding which process runs on the CPU and when.

IPC

Inter-Process Communication between processes for synchronization and data exchange.

Multiprogramming

Running several programs by partitioning memory and switching the CPU when a program waits for I/O.

Multitasking

Time-sharing extension that enables interactive use by rapidly switching between tasks using a timer.

Time-sharing

A method to share a computer among multiple users by rapid context switching.

Virtual Memory

Allows programs to be larger than physical memory by loading parts on demand; active data may be swapped to disk, giving a uniform address space.

Spooling

Stands for Simultaneous Peripheral Operation On-Line; overlaps I/O with computation by using disk as a buffer.

Job pool

Data structure containing information and pointers to jobs on disk, enabling scheduling to improve CPU utilization.

Real-Time Systems

Systems with deterministic, fixed-time constraints represented by hard or soft real-time requirements.

Hard real-time

Deterministic, fixed-time constraints with limited or absent secondary storage; not well suited to general-purpose time-sharing.

Soft real-time

Real-time constraints useful for applications like multimedia or VR and requiring OS support but less strict than hard real-time.

Distributed Systems

Computing distributed among several processors with local memory; processors communicate over networks; benefits include resource sharing, speed, and reliability.

Network Operating System (NOS)

An OS that provides file sharing and communication services and runs independently on each computer in a network.

Distributed Operating System (DOS)

An OS that makes the network appear as a single operating system with coordinated control across computers.

Symmetric multiprocessing (SMP)

Multiple identical copies of the OS running; many processes can run at once without performance deterioration.

Asymmetric multiprocessing

Master processor schedules and allocates work to slave processors; common in very large systems.

Parallel systems (5th generation)

Multiprocessor systems with more than one CPU in close communication; tightly coupled with shared memory; higher throughput and reliability.

UI (User Interface)

The means by which a user interacts with the OS, examples include X Windows and MS Windows.

File System

Part of the OS that manages files and directories and access to storage.

Multimedia Support

OS features to support multimedia applications.

Internet Browser

An application that runs on the OS to access and display web content.

Virtual machine

A hardware abstraction that provides a simulated hardware platform for software to run on.