Introduction to Operating Systems and Computer Information Systems

Comprehensive vocabulary flashcards covering the components of Computer Information Systems, operating system history, architecture designs (monolithic, modular, virtual machines), GNU/Linux structure, and file system principles.

Hardware Architecture Interconnection

The organization of computer hardware where the central memory (C.M) is connected to both the central processing unit (CPU) and input/output (I/O) units via buses that transfer exchanged data and instructions.

Hardware (Computer Information System)

A machine capable of automatically processing information, commonly called a "computer," consisting of three main parts: central memory, processor (CPU), and input/output units.

Central Memory

The hardware component responsible for holding applications (programs and their data) while they are executed.

Processor (CPU)

The hardware component that executes the instructions of applications loaded in the central memory.

Input/Output Units

Hardware components that enable data exchange between peripheral devices or users and the central memory.

Buses

Communication channels that connect hardware components together to transfer data and instructions between them.

Applications

Programs initially stored on a storage device that must be loaded into central memory to be executed sequentially, one instruction after another, by the processor.

Operating System (O.S.)

A set of software tools (programs) acting as an intermediary between the user and computer, coordinating hardware resources, managing essential tasks, and providing a user-friendly interface.

Stone Computers (1950–1960)

The early computing era where no operating system existed, requiring direct interaction where human operators had to learn and input the machine's binary language.

Programming Language Levels

The structural hierarchy of programming languages spanning from the lowest level (Machine Language with binary $0, 1$), to Assembly Language (using instructions like INT, ADD, MOV), high-level human-approaching languages (C, Pascal, Python, Java), up to Human language at the highest level.

UNIX (1969)

An operating system initially written in assembly language in 1969 by Ken Thompson with the goal of creating a multitasking and multi-user OS.

Multitasking

An operating system capability that allows several programs to execute at the same time.

Multi-user

An operating system capability that allows several users to use the system at the same time.

C Programming Language (1972)

A high-level programming language written by Dennis Ritchie in 1972, used in 1973 by Thompson and Ritchie to rewrite $90\%$ of UNIX ($90\%\text{ C} + 10\%\text{ assembly}$) to make it portable across different hardware architectures.

MS-DOS (1981)

Microsoft's initial operating system (Micro-Soft-Disk OS) created for the IBM-PC and compatibles, featuring a textual user interface that was single-tasking and single-user.

GNU Project (1983)

A project launched by Richard Stallman to create a UNIX-equivalent, free (libre) operating system based on four fundamental software freedoms (Freedoms 0, 1, 2, and 3).

System (1984)

Apple's initial operating system released for Macintosh PCs, representing the first PC operating system to feature a Graphical User Interface (GUI), with multitasking and single-user support.

POSIX (1988)

Portable Operating System Interface; a standard established in 1988 to define interface standards across UNIX operating systems.

Linux Kernel (1991)

A multitasking and multi-user operating system kernel written by Linus Torvalds for i386 architecture PCs, released under the free GNU General Public License (GNU GPL).

GNU/Linux Distribution

A complete operating system package designed to simplify OS installation, including the Linux Kernel, GNU project programs, a Graphical User Interface, and distribution-specific software.

Windows 95

A Microsoft operating system released in 1995 that transitioned Microsoft's GUI from an MS-DOS add-on into a full multitasking and single-user operating system.

Ubuntu (2004)

A popular GNU/Linux distribution based on Debian, designed to provide a simple, intuitive, and secure user interface.

Android OS (2008)

A mobile operating system launched by Google based on the Linux kernel, originally featuring a GUI written in Java, which was replaced by Kotlin in 2017.

Peripheral Devices

Hardware components that enable the computer to exchange information (communicate) with the user or other computers on a network.

Device Management

An OS function covering the installation, configuration, and abstraction of peripheral units to hide hardware differences between manufacturers.

System Space vs. User Space

The two primary memory partitions created by the memory manager: System space, which holds the OS itself, and User space, which contains the programs executed by users.

Process

A dynamic image or copy of a program loaded into the central memory for execution, which evolves over time through a series of states.

Process Management

Operating system services that monitor the progression of processes from their creation (birth) to termination (death), handling state changes, communications, and synchronization.

File

A set of data of the same type, encoded and saved on a storage device, categorized primarily into program files and data files.

Program Files

Files containing instructions directly understood by the machine or the OS, expressed either in machine language (binary) or in a high-level command source language.

Data Files

Files containing information that the machine or OS cannot interpret directly, requiring execution via an associated program file (such as a text data file requiring a text editor).

Command Interpreter

A program specialized in analyzing user commands entered via an interface to either trigger execution if valid or return an error message if invalid.

Monolithic OS Architecture

An operating system design consisting of a single structure organized into 3 levels: the main function (handling supervisor calls/SVC), service functions (handling specific system calls), and utility functions.

Modular Monolithic Systems

An evolved OS architecture where core system functions remain grouped in a monolithic structure while hardware drivers are separated into independent modules to avoid rewriting the entire OS for updates.

Virtual Machine Monitor (VMM)

An operating system layer that runs directly on top of physical hardware and provides upper layers with multiple virtual machines, intercepting virtual hardware operations to execute them physically.

GNU/Linux Internal Structure

The three independent structural parts of a GNU/Linux OS: the Kernel (central program managing resources), the Command Interpreter/Shell (user interaction interface), and Utility Programs (basic tools).

Primitives

Basic low-level functions provided by the operating system kernel to other programs, invoked through system calls.

Shell

The command interpreter in GNU/Linux that reads and executes commands; common types include the Bourne shell (sh, default on UNIX), Bourne Again Shell (Bash, default on GNU/Linux), and C shell (csh, default on BSD UNIX).

Internal Commands

Commands implemented directly within the command interpreter that are executed without launching an external file.

External Commands

Commands implemented in separate executable files that the shell must launch into central memory to execute.

File System

A method of storing information and organizing it into files on storage devices, providing users with an abstract view of data and locating it using file paths.

FAT (File Allocation Table)

The default file system originally developed for MS-DOS, which later evolved into FAT32 in Microsoft Windows.

NTFS (New Technology File System)

The default file system designed for modern versions of Microsoft Windows, starting from Windows NT, 2000, and XP.

ext (Extended File System)

The default file system family for GNU/Linux, currently implemented in its 4th version as ext4.

Directory Files

Specialized files in GNU/Linux that contain references and addresses pointing to other files or subdirectories.

Special Files

Files established by the operating system that serve as access points to hardware peripheral devices, managed via communication drivers.

Symbolic-Link Files (Soft Links)

Files containing only a reference (address) pointing to another file, allowing that file to be accessed under multiple names without duplicating content on the disk.

Root Directory ($/$)

The top-most directory in a hierarchical tree-structured file system, represented by the slash character ($/$), which is the only directory that has no parent directory.