Installation, Security, & Package Management (U4)

Unit 4

ISO Image

A disk image file used for operating system booting and installation.

Virtual Machine

A computer system created using software on a physical computer to emulate separate physical hardware functionality.

Firmware

A type of software that is embedded into hardware devices to control their core functionality.

Boot Process

The sequential process in which a computer system initializes hardware and loads the operating system kernel into memory.

BIOS (Basic Input/Output System)

Legacy 32-bit system firmware that initializes hardware and provides a system setup interface for configuring boot devices.

UEFI (Unified Extensible Firmware Interface)

Modern system firmware providing support for 64-bit CPU operation at boot, full GUI/mouse interaction, and enhanced boot security.

Boot Loader

A small program stored in ROM or storage that loads the kernel from a storage device into memory at startup.

Bootable Disk

A physical device (often USB or CD/DVD) containing an operating system installer image used for Linux installation.

PID (Process Identifier)

A unique numerical ID assigned by the kernel to each running process on the system.

Confidentiality

The principle of protecting sensitive information from unauthorized access or disclosure, ensuring that only authorized individuals have access to it.

Integrity

The assurance that data is accurate and unaltered during storage, transmission, or processing.

Availability

The principle that ensures reliable access to information and resources when needed, minimizing downtime and preventing service interruptions.

auth.log

A log file in Linux systems that records authentication-related events.

journalctl

The command-line utility in Linux used to query and display messages from the journal, which logs system events and services.

ps

A command in Linux used to display information about currently running processes, including their status and resource usage.

top

A command in Linux that provides a real-time view of system processes, displaying their resource usage, such as CPU and memory.

Signal

A notification sent to a process in Linux, either to trigger an action or to communicate events such as termination.

pkil

A command in Linux used to kill a process by its process ID (PID), allowing you to terminate running applications.

apt

A package management tool in Debian-based Linux distributions used to install, upgrade, and remove software packages.

dpkg

A low-level package management tool in Debian-based systems that enables the installation, removal, and management of .deb packages.