Operating System Midterms

Operating System (OS)

Primary system software that manages computer hardware, software resources, and provides common services for computer programs.

Process Management

OS function that decides which programs run, allocation of CPU time, and execution duration (The Task Manager).

Memory Management

OS function that hands out chunks of short-term memory (RAM) to programs and cleans up space upon program termination (The Scratchpad Organizer).

File System Management

OS function that organizes documents, photos, and apps into folders and tracks physical disk storage (The Digital Filing Cabinet).

Device Management

OS function that acts as a middleman between software and physical hardware using drivers (The Translator).

Security and Access Control

OS function that checks passwords/fingerprints and sets permissions to protect private files (The Security Guard).

Networking

OS function that packages data and sends it over Wi-Fi or cables for web loading and streaming (The Post Office).

System

Overarching, integrated collection of hardware, OS software, utilities, and application packages.

Program

A passive entity stored on disk (e.g., .exe file) waiting to be loaded into memory.

Process

An active instance of a program in execution, combined with tasks, memory space, and CPU time.

Thread

The fundamental unit of CPU execution within a process (lightweight process) sharing memory space.

Text Section (Code)

Contains compiled executable code/binary instructions read from disk (usually read-only).

Data Section

Stores global and static variables that persist throughout the application's lifetime.

Heap

Dynamically allocated memory requested at runtime (grows upward toward higher memory addresses).

Stack

Stores temporary data like local function variables and return addresses (grows downward, LIFO).

CPU Registers

Hardware storage locations inside the CPU populated only when the process is actively executing.

Multitasking

The ability to execute multiple processes concurrently by rapid CPU time-sharing.

Process Isolation

Enforces strict memory boundaries so one crashing process cannot overwrite another's data.

New State

Process state where it is being created and initialized.

Ready State

Process state where it is loaded into RAM and waiting to be assigned CPU time by the scheduler.

Running State

Process state where instructions are actively being executed by the CPU core.

Waiting (Blocked) State

Process state when execution is paused waiting for an event or I/O completion.

Terminated (Exit) State

Process state when execution has completed or aborted and resources are reclaimed.

Process Control Block (PCB)

Fundamental data structure maintained by the OS kernel for every active process containing its PID, state, PC, and registers.

FIFO / FCFS Scheduling

CPU scheduling algorithm where processes execute strictly in the order of arrival (non-preemptive).

Convoy Effect

Disadvantage of FIFO where short processes get stuck behind a long CPU-bound process.

GUI (Graphical User Interface)

Visual interface using Windows, Icons, Menus, and Pointer (WIMP).

CLI (Command Line Interface)

Text-based interface requiring user commands; highly resource-efficient and scriptable.

MVC Model Component

Manages raw data, business logic, variables, state, and identifiers.

MVC View Component

Renders the visual presentation and User Interface (UI) to the user.

MVC Controller Component

Handles user inputs, triggers, and events, bridging the Model and View.