Introduction to Operating Systems – Flashcards (VOCABULARY)

Vocabulary flashcards covering key OS concepts from the lecture notes.

Operating System (OS)

A program that acts as an intermediary between a user and computer hardware, with goals to execute user programs, provide a convenient environment, and use hardware efficiently.

Hardware

The physical layer of a computer system, including the CPU, memory, I/O devices, and other components.

Application programs

Software that users interact with directly and that use system resources via the operating system (e.g., word processors, browsers).

Users

People, machines, or other computers that interact with the system through application programs.

Kernel

The core part of the OS that talks directly to hardware and manages CPU, memory, devices, and system calls.

Resource Allocator

The OS component that assigns CPU time, memory space, disk storage, and I/O devices to programs and users to ensure fair and efficient use.

Control Program

The part of the OS that enforces rules and coordinates hardware and software, managing execution of programs.

Interrupt

A signal from hardware or software that temporarily stops the CPU to handle a high-priority event.

Interrupt Vector

A table in memory that holds the addresses of interrupt handlers for different interrupt types.

Interrupt Service Routine (ISR)

The OS routine that handles a specific interrupt.

Device Driver

Software that translates between the OS and a device controller so commands are understood by the hardware.

Device Controller

Hardware that manages a specific I/O device and communicates with the CPU and memory, often with a local buffer.

Local Buffer

A small memory area in a device controller used to temporarily hold data during transfer.

Buffer

Temporary storage used to hold data as it moves between memory and devices.

I/O Device

An input or output device such as keyboard, mouse, disk, or printer.

Memory Management

The OS responsibility to allocate and manage memory for running programs.

Process Scheduling

Deciding which process runs at any given time to ensure efficient use of CPU.

Device Management

Coordinating and controlling communication with hardware devices.

System Calls

Requests from applications to the OS to perform services; the OS handles them as interrupts or traps.

Trap/Exception

A software-generated interrupt representing errors or a request for OS service.

Blocking I/O

A method where the program waits (is blocked) until the I/O operation completes before continuing.

Asynchronous (Non-blocking) I/O

An I/O approach where the program can continue executing while I/O proceeds in the background; completion is signaled via interrupts or polling.

Interrupt-driven I/O Cycle

The sequence where a device starts an I/O, the device signals completion with an interrupt, the ISR handles it, and the CPU resumes the interrupted task.

I/O Structure

Two methods for handling I/O: blocking (waits for completion) or asynchronous (continues and is notified later).

Middleware

Software frameworks included with OS that provide services to applications (e.g., databases, graphics, multimedia).

Embedded System

Special-purpose computers with little or no user interface, often running in real-time (e.g., car ECUs).

Minimal/No User Interface

Embedded systems often have no traditional UI and run predefined tasks automatically.

Mobile Operating System

OS designed for mobile devices; resource-poor, optimized for usability and battery life, with power-saving features.

Dedicated Systems vs Shared Resources

Workstations have dedicated hardware/resources; servers provide shared resources managed by OS.

Free/Libre and Open-Source OS (FLOSS)

OS whose source code is freely available and modifiable (e.g., Linux, BSD).

Security and Protection

Mechanisms in the OS to prevent unauthorized access and protect system integrity.

Virtualization

Technique to create virtual hardware/resources to support multiple environments.

Distributed Systems

Systems that use multiple interconnected computers to share resources and coordinate tasks.

Kernel Data Structures

Internal data structures used by the kernel to manage resources and scheduling.

I/O Controller

Hardware component that manages a specific device; has a local buffer and communicates with the CPU.

Device Driver Example

Software that translates OS requests to a device controller’s commands (e.g., printer driver translates print requests).

OS as Resource Manager

The OS acts as a manager ensuring hardware and software components work together smoothly.

Interrupt Architecture

System design that saves the interrupted instruction’s address and transfers control to an interrupt handler.

Interrupt Vector Table

Table listing addresses of interrupt handlers for each interrupt type.