OS Fundementals

Embedded Operating System (OS)

An operating system designed for specialized devices dedicated to specific tasks, such as banking machines or industrial control systems.

Firmware

Specific software installed on device hardware like fitness monitors or routers, providing essential functionality and control.

Hypervisor

Software that enables the creation and management of virtual machines, allowing multiple operating systems to run on a single physical machine simultaneously.

Kernel

The core component of an operating system that manages resources and acts as an interface between software applications and hardware.

Mobile OS

Operating systems tailored for mobile devices like smartphones and tablets, optimized for touch-based interaction and app efficiency.

Operating System (OS)

Software that manages hardware resources and provides services for computer programs, facilitating user interaction and software execution.

Shell

The interface that allows users to interact with an operating system, typically through command-line interfaces.

Type 1 Hypervisor

A bare-metal hypervisor that operates directly on hardware, enabling the creation and management of multiple virtual machines; examples include VMware ESXi and Microsoft Hyper-V.

Type 2 Hypervisor

A hypervisor that requires a host operating system and runs as an application within it, facilitating virtual machine creation and management; examples include Oracle, VM VirtualBox, and VMware Workstation.

Virtual Machine (VM)

A software emulation of a physical computer that operates within a host environment, allowing multiple operating systems to run concurrently on a single physical machine.

Application Hardware Interface

The intermediary layer between software applications and hardware components, facilitating interaction and functionality.

Application Programming Interface (API)

A set of protocols and tools that allows different software applications to communicate and integrate, enhancing interoperability and development efficiency.

CPU Usage

The percentage of time the central processing unit (CPU) spends executing instructions for a specific task or process, indicating the load or demand on the CPU.

Disk Management

A Windows utility that manages disk drives, partitions, and volumes, enabling tasks like creating, formatting, resizing, and deleting volumes.

File System

A method or structure for organizing and storing computer files on storage devices, such as hard drives, SSDs, or removable media, defining how data is accessed and stored.

Hardware Abstraction Layer (HAL)

A software layer that abstracts hardware details and provides a consistent interface for the OS to interact with different hardware configurations.

Hardware Configuration

The arrangement and setup of physical hardware components within a computer system, including connections, settings, and compatibility considerations.

Input/Output (I/O)

The process of exchanging data between an information processing system (such as a computer) and the outside world, typically through peripherals like keyboards, mice, or printers.

Application Hardware Interface

The intermediary layer between software applications and hardware components, facilitating interaction and functionality.

Application Programming Interface (API)

A set of protocols and tools that allows different software applications to communicate and integrate, enhancing interoperability and development efficiency.

CPU Usage

The percentage of time the central processing unit (CPU) spends executing instructions for a specific task or process, indicating the load or demand on the CPU.

Disk Management

A Windows utility that manages disk drives, partitions, and volumes, enabling tasks like creating, formatting, resizing, and deleting volumes.

Driver

Software that enables an OS to communicate with hardware devices by translating commands from the OS into instructions that the hardware can understand and execute.

Input/Output (I/O)

The process of exchanging data between an information processing system (such as a computer) and the outside world, typically through peripherals like keyboards, mice, or printers.

Memory Management

The process of managing computer memory resources to optimize system performance, involving tasks like allocation, deallocation, and usage monitoring of RAM.

Multitasking

The ability of an OS to execute multiple tasks or processes concurrently, allowing users to run multiple applications simultaneously.

Process Management

Involves managing processes running on a computer, including tasks such as starting, stopping, prioritizing, and monitoring processes to ensure efficient use of system resources.

Print Driver

A type of driver specifically designed to facilitate communication between an OS and a printer, ensuring proper printing functionality.

Processor Scheduling

The process by which the OS allocates CPU time to processes, managing their execution and priority levels to optimize system performance and responsiveness.

Software Application

A program or group of programs designed to perform specific tasks or functions for the user or another application.

System Resources

The collective hardware, software, and network components of a computer system that enable it to perform tasks, including CPU, memory (RAM), disk storage, and network connectivity.

System Software

Software that provides a platform for other software to run on, including OSs, utilities, and hardware drivers.

Task Manager

A system utility in Windows that provides information about processes and applications running on the computer, allowing users to monitor system performance, manage running processes, and terminate tasks if necessary.

API

Application Programming Interface

Access Control

The practice of restricting access to resources or areas only to authorized entities, ensuring data security and integrity.

Access Control Models

Frameworks or methodologies used to enforce access control policies, such as discretionary access control (DAC), mandatory access control (MAC), role-based access control (RBAC), and attribute-based access control (ABAC).

Add a Device

An option to install new hardware devices, typically via Bluetooth or wireless connections.

App and Features

A section in the settings app for viewing and managing installed applications.

Authentication

The process of verifying the identity of a user or device trying to access a system, typically through usernames, passwords, or other credentials.

Authorization

The process of granting or denying specific privileges and permissions to authenticated users or systems based on their identity and roles.

Back Driver

A feature to revert to the previous driver version if an update causes issues.

Bluetooth and Devices

A section in the settings app for managing connected devices such as printers, scanners, and USB devices.

Default Apps

An option in the settings app that is used to open specific file types or perform certain tasks.

Device Manager

A Windows tool for managing hardware devices and their drivers.

Explicit Deny

A specific access control setting that prevents a user or group from accessing a resource, overriding any permissions that might otherwise allow access.

Group Level

Managing user permissions and access rights by categorizing users into groups based on shared attributes such as department or job role.

Inheritance

The principle where permissions set at a higher level in a hierarchy (e.g., folder) are automatically passed down to lower levels (e.g., files within that folder) unless explicitly overridden.

Permission

A setting that defines a user or group's actions, typically categorized as allow or deny.

Plug and Play

A feature that allows the OS to detect and configure newly attached hardware devices automatically.

Resource Ownership

The concept that specifies who controls a resource and can dictate access permissions, often the resource's creator.

Settings App

A Windows interface for configuring various system settings, including devices and applications.

Update Driver

A process to install the latest driver for a device.

User Management

The process of creating, modifying, and deleting user accounts, as well as assigning rights and permissions to these accounts within a computing environment.

The User Management Control Models

1. Discretionary Access Control (DAC)

2. Mandatory Access Control (MAC)

3. Role-Based Access Control (RBAC)

4. Attribute-Based Access Control (ABAC)

Discretionary Access Control (DAC)

Access to data and resources are at the discretion of the owner. In a networked environment, access to company/organization data and resources will be at the discretion of network administrators.

Mandatory Access Control (MAC)

Based on a level of clearance, or tier, within your organization.

Role-Based Access Control (RBAC)

Similar to MAC, but instead determined by job functionality.

Attribute-Based Access Control (ABAC)

Similar to RBAC, but often includes additional factors such as location or region. An example could be a support group, but having different support roles (HQ Support, Branch Office Support).

Allocation Unit

A unit of disk space into which files are divided for storage, typically called clusters or blocks.

Attributes

Additional metadata associated with files beyond the data, such as creation date, author, size, and permissions.

Cluster

A group of sectors on a storage device, typically the smallest unit of storage that can be allocated to a file.

Common Linux File Systems

EXT2, EXT3, EXT4, XFS, Btrfs

Common Mac File Systems

HFS, HFS+, APFS

Common Windows File Systems

FAT, FAT32, exFAT, NTFS

Compression

The process of reducing the size of a file or files to save disk space, achieved by encoding repetitive data into a more compact form.

Encryption

A method of securing data by transforming it into an unreadable format using cryptographic algorithms, requiring a unique key to decrypt and access the original data.

File Allocation Table (FAT)

File system used primarily by early versions of Microsoft OSs, defining how files are organized and managed.

Journaling

A technique used by file systems to record changes made to data before they are committed to disk, aiding in recovery after system failures or crashes.

File Limitations

Restrictions or constraints imposed by file systems or OSs on aspects such as file naming conventions, supported characters, and maximum file sizes.

Metadata

Information about a file stored by the file system, including attributes such as size, location, and time stamps.

Naming Rules

Guidelines and conventions governing how files and directories should be named within a file system, including character limits, allowed symbols, and reserved keywords.

New Technology File System (NTFS)

The predominant file system used by modern Windows OSs, known for supporting large partitions, file sizes, and security features like permissions.

Partition

A logical division of a physical disk into independent areas, each with its own file system, used to organize and manage data.

Permissions

Access rights determining who can read, write, execute, or modify files and directories on a computer system.

Sector

The smallest unit of storage on a disk, typically 512 bytes, which can store a fixed amount of data.

Versioning

A method to track changes to files over time, allowing users to access previous versions or roll back to earlier states.