Foundations of Computer Science

Kernel

the core component of an OS that manages resources and acts as an interface between software apps and hardware.

Shell

the interface that allows users to interact with an OS, typically through command-line interfaces.

Operating system (OS

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

Mobile OS

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

Embedded OS

found in specialized devices that are dedicated to specific tasks (ATMS, public kiosks).

Firmware

a specified OS for a specific type of device providing essential functionality and control. Usually for smaller, more portable devices such as fitness monitors, GPSs, printers or routers.

Hypervisor

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

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.

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.

Application hardware interface

the intermediary layer between software apps and hw components, facilitating interaction and functionality.

Application programming interface (API)

a set of protocols and tools that allows different sw apps to communicate and integrate, enhancing interoperability and development efficiency.

CPU usage

the percentage for 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 hw devices by translating commands from the OS into instructions that the hw can understand and execute.

File system

a method of 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 sw layer that abstracts hw details and provides a consistent interface for the OS to interact with different hw configurations.

Hardware configuration

the arrangement and setup of physical hw 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.

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 process 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 app.

System resources

the collective hw, sw, 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 sw to run on, including OSs, utilities, and hardware drivers.

Task manager

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

Access control

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

Access control models

the frameworks or methodologies used to enforce access control policies, such as:

o Discretionary Access Control (DAC)

o Mandatory Access Control (MAC)

o Role-Based Access Control (RBAC)

o 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 apps.

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 or 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.

Driver

sw that allows the OS to communicate with hardware devices.

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.

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

EXT 2/3/4 (Extended File Systems), XFS - journaled file system, Btrfs (Better File System)

Common Mac file systems

HFS (hierarchical file system), HFS+, APFS (Apple File system)

Common Windows file systems

FAT (File Allocation Table), FAT32, exFAT - extended FAT and NTFS, NTFS - most common system

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, require 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 made to data before they are committed to disk, aiding in recovery after system failures or crashes.

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.

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.

Access Control List (ACL)

a list of permissions attached to an object that specifies which users or system processes can access it.

Cipher

a command-line tool used to manage encryption and decryption of files on NTFS volumes.

Disk quota

a feature that allows administrators to limit the amount of disk space a user can use.

EFS

encrypting file system, a feature of NTFs that provides file system-level encryption.

File system driver

a component of the OS that provides an interface for apps to read and write to disk storage.

Action

the operation performed by a scheduled task, which can include starting a program, sending an email, or displaying a message.

Background processes

operations running in the background to support system and app functionalities.

Computer management

a windows tool for managing system components, including services, storage, and performance.

Create basic task wizard

a guided interface within Task Scheduler that helps users create a new scheduled task by following a series of steps.

DHCP client

a service that automatically obtains and updates the device's IP addresses and DNS records.

Disk percentage

the percentage of disk I/O activity generated by a process

CPU percentage

the percentage of CPU resources allocated to a specific process.

Domain name system (DNS)

a hierarchical and decentralized naming system for computers, services, or other resources connected to the internet or a private network.

Dynamic host configuration protocol (DHCP)

a network management protocol for dynamically assigning device IP addresses.

Executable file

a file containing a program that the computer can execute or run.

Print spooler

a service that manages print jobs and interactions with printers on the system.

Program/script

an executable file or script specified in the Action step that the scheduled task will run.

Resource-Intensive

describing a process that consumes a significant amount of CPU, memory, disk, or network resources.

Services console

a dedicated interface within Computer Management for viewing and managing installed services.

Task scheduler

a Windows utility that schedules automated tasks to run at specified times or events.

Task scheduler library

the central repo within Task Scheduler where all created tasks are stored and managed.

Trigger

a condition or event that starts executing a scheduled task, such as a specific time, daily recurrence or system event.

Drivers

sw components that enable communication between the OS and hw devices.

Arguments/parameters/switches

additional options or settings that modify a command's operation.

Automation

using scripts and commands to perform tasks automatically, without manual intervention

Cd (change directory)

a command to change the current working directory.

Chkdsk

a command used to check the integrity of the disk and repair any found errors.

Cmdlet

a lightweight command used in the PowerShell environment, following a verb-noun syntax.

Command-line interface (CLI)

a text-based interface used to interact with the computer by typing commands

Command prompt

a text-based interface that allows users to interact with the OS using commands.

Commands

instructions typed into a CLI to perform specific tasks requiring precise syntax and parameters.