RHCSA Acronyms and Glossary

Comprehensive list of acronyms, abbreviations, and key terms for RHCSA exam preparation

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Alphabetical Index

A

  • ACL - Access Control List - Extended file permissions beyond standard Unix permissions
  • API - Application Programming Interface - Set of protocols for building software applications
  • ARP - Address Resolution Protocol - Maps IP addresses to MAC addresses
  • AVC - Access Vector Cache - SELinux component that caches access decisions
  • AWK - Aho, Weinberger, and Kernighan - Pattern scanning and processing language

B

  • BASH - Bourne Again Shell - Default command interpreter in RHEL
  • BIOS - Basic Input/Output System - Legacy firmware interface for PC boot
  • BIND - Berkeley Internet Name Domain - DNS server software
  • BTRFS - B-tree File System - Copy-on-write filesystem (not default in RHEL)

C

  • CD - Change Directory - Command to navigate filesystem
  • CIDR - Classless Inter-Domain Routing - IP addressing and routing methodology
  • CLI - Command Line Interface - Text-based interface for system interaction
  • CPU - Central Processing Unit - Main processor of a computer
  • CRON - Command Run On - Time-based job scheduler
  • CSV - Comma-Separated Values - File format for tabular data

D

  • DAC - Discretionary Access Control - Standard Linux permissions model
  • DHCP - Dynamic Host Configuration Protocol - Automatic IP address assignment
  • DMZ - Demilitarized Zone - Network security zone
  • DNF - Dandified YUM - Modern package manager for RHEL 8/9
  • DNS - Domain Name System - Translates domain names to IP addresses
  • DOS - Disk Operating System - Legacy operating system

E

  • EFI - Extensible Firmware Interface - See UEFI
  • EOF - End of File - Marker indicating no more data
  • EPM - Enterprise Package Manager - Package management tool
  • EXT4 - Fourth Extended Filesystem - Linux filesystem type

F

  • FDISK - Fixed Disk - Disk partitioning utility
  • FIFO - First In, First Out - Named pipe for inter-process communication
  • FQDN - Fully Qualified Domain Name - Complete domain name including hostname
  • FSCK - File System Check - Filesystem integrity checker
  • FTP - File Transfer Protocol - Network protocol for file transfer

G

  • GCC - GNU Compiler Collection - Compiler system
  • GID - Group Identifier - Numeric group identification
  • GNU - GNU's Not Unix - Free software project
  • GPG - GNU Privacy Guard - Encryption and signing tool
  • GPL - General Public License - Free software license
  • GPT - GUID Partition Table - Modern disk partitioning scheme
  • GRUB - Grand Unified Bootloader - Linux boot loader
  • GUI - Graphical User Interface - Visual interface for system interaction
  • GUID - Globally Unique Identifier - Unique reference number

H

  • HDD - Hard Disk Drive - Mechanical storage device
  • HOME - Home Directory - User's personal directory
  • HTML - HyperText Markup Language - Web page formatting language
  • HTTP - HyperText Transfer Protocol - Web communication protocol
  • HTTPS - HTTP Secure - Encrypted web communication protocol

I

  • ICMP - Internet Control Message Protocol - Network diagnostic protocol (ping)
  • IDE - Integrated Drive Electronics - Legacy disk interface
  • I/O - Input/Output - Data transfer operations
  • IP - Internet Protocol - Network layer protocol
  • IPC - Inter-Process Communication - Process interaction mechanisms
  • IPv4 - Internet Protocol version 4 - 32-bit IP addressing
  • IPv6 - Internet Protocol version 6 - 128-bit IP addressing
  • ISO - International Organization for Standardization - Standards body

J

  • JSON - JavaScript Object Notation - Data interchange format
  • JVM - Java Virtual Machine - Java runtime environment

K

  • KB - Kilobyte - 1024 bytes
  • KVM - Kernel-based Virtual Machine - Linux virtualization technology

L

  • LAMP - Linux, Apache, MySQL, PHP - Web application stack
  • LDAP - Lightweight Directory Access Protocol - Directory service protocol
  • LIFO - Last In, First Out - Stack data structure
  • LTS - Long Term Support - Extended support release
  • LUKS - Linux Unified Key Setup - Disk encryption specification
  • LV - Logical Volume - LVM storage unit
  • LVM - Logical Volume Manager - Flexible disk management system

M

  • MAC - Mandatory Access Control - SELinux security model
  • MAC - Media Access Control - Hardware network address
  • MB - Megabyte - 1024 kilobytes
  • MBR - Master Boot Record - Legacy boot sector (2TB limit)
  • MCS - Multi-Category Security - SELinux security model
  • MD5 - Message Digest 5 - Cryptographic hash function
  • MLS - Multi-Level Security - SELinux security model
  • MTU - Maximum Transmission Unit - Largest packet size

N

  • NAT - Network Address Translation - IP address remapping
  • NFS - Network File System - Distributed filesystem protocol
  • NIC - Network Interface Card - Network adapter hardware
  • NIS - Network Information Service - Directory service
  • NMCLI - NetworkManager Command Line Interface
  • NMTUI - NetworkManager Text User Interface
  • NTP - Network Time Protocol - Time synchronization protocol

O

  • OCI - Open Container Initiative - Container standards organization
  • OS - Operating System - System software managing hardware/software
  • OSS - Open Source Software - Publicly accessible source code

P

  • PAM - Pluggable Authentication Modules - Authentication framework
  • PATH - Path Variable - Executable search directories
  • PCI - Peripheral Component Interconnect - Expansion card standard
  • PE - Physical Extent - LVM allocation unit
  • PID - Process Identifier - Unique process number
  • PING - Packet Internet Groper - Network connectivity test
  • PPID - Parent Process Identifier - Parent process number
  • PS - Process Status - Process listing command
  • PV - Physical Volume - LVM physical storage

Q

  • QEMU - Quick Emulator - Machine emulator and virtualizer

R

  • RAID - Redundant Array of Independent Disks - Data redundancy/performance
  • RAM - Random Access Memory - System memory
  • RBAC - Role-Based Access Control - Security model
  • REGEX - Regular Expression - Pattern matching syntax
  • RHCSA - Red Hat Certified System Administrator - Entry-level certification
  • RHCE - Red Hat Certified Engineer - Advanced certification
  • RHEL - Red Hat Enterprise Linux - Enterprise Linux distribution
  • RPM - Red Hat Package Manager - Package format and tool
  • RSA - Rivest-Shamir-Adleman - Public-key cryptosystem
  • RSS - Resident Set Size - Memory usage metric
  • RSYNC - Remote Sync - File synchronization tool

S

  • SAMBA - Server Message Block - Windows file sharing on Linux
  • SATA - Serial Advanced Technology Attachment - Disk interface
  • SCSI - Small Computer System Interface - Storage interface standard
  • SED - Stream Editor - Text processing tool
  • SELinux - Security-Enhanced Linux - Mandatory access control system
  • SFTP - SSH File Transfer Protocol - Secure file transfer
  • SHA - Secure Hash Algorithm - Cryptographic hash functions
  • SHELL - Command interpreter - User interface for OS access
  • SKEL - Skeleton - Template directory for new users
  • SMTP - Simple Mail Transfer Protocol - Email transmission protocol
  • SNMP - Simple Network Management Protocol - Network management
  • SSD - Solid State Drive - Flash-based storage device
  • SSH - Secure Shell - Encrypted remote access protocol
  • SSL - Secure Sockets Layer - Deprecated encryption protocol
  • STDIN - Standard Input - Input stream (file descriptor 0)
  • STDOUT - Standard Output - Output stream (file descriptor 1)
  • STDERR - Standard Error - Error stream (file descriptor 2)
  • SUDO - Superuser Do - Privilege escalation command
  • SWAP - Swap Space - Disk-based virtual memory
  • SYSTEMD - System Daemon - Init system and service manager

T

  • TAR - Tape Archive - Archive file format and tool
  • TCP - Transmission Control Protocol - Reliable network protocol
  • TLS - Transport Layer Security - Modern encryption protocol
  • TMP - Temporary - Temporary files directory
  • TTY - Teletypewriter - Terminal device
  • TUI - Text User Interface - Text-based graphical interface
  • TZ - Time Zone - Timezone environment variable

U

  • UDP - User Datagram Protocol - Connectionless network protocol
  • UEFI - Unified Extensible Firmware Interface - Modern firmware standard
  • UID - User Identifier - Numeric user identification
  • UMASK - User Mask - Default permission mask
  • URI - Uniform Resource Identifier - Resource identifier
  • URL - Uniform Resource Locator - Web address
  • USB - Universal Serial Bus - Peripheral connection standard
  • UTF - Unicode Transformation Format - Character encoding
  • UUID - Universally Unique Identifier - Unique device/filesystem ID

V

  • VDO - Virtual Data Optimizer - Deduplication and compression
  • VG - Volume Group - LVM storage pool
  • VI/VIM - Visual/Vi Improved - Text editor
  • VLAN - Virtual Local Area Network - Network segmentation
  • VM - Virtual Machine - Virtualized computer system
  • VNC - Virtual Network Computing - Remote desktop protocol
  • VPN - Virtual Private Network - Secure network connection

W

  • WAN - Wide Area Network - Large geographic network
  • WWW - World Wide Web - Global information system

X

  • X11 - X Window System Version 11 - Graphical display system
  • XFS - X File System - High-performance filesystem (RHEL default)
  • XML - Extensible Markup Language - Data format

Y

  • YAML - YAML Ain't Markup Language - Data serialization format
  • YUM - Yellowdog Updater Modified - Legacy package manager

Z

  • ZLIB - Compression Library - Data compression library
  • ZFS - Zettabyte File System - Advanced filesystem (not in RHEL)

Acronyms by Category

Certification & System

  • RHCSA - Red Hat Certified System Administrator
  • RHCE - Red Hat Certified Engineer
  • RHEL - Red Hat Enterprise Linux
  • OS - Operating System
  • CLI - Command Line Interface
  • GUI - Graphical User Interface
  • API - Application Programming Interface
  • FQDN - Fully Qualified Domain Name
  • TTY - Teletypewriter (terminal)
  • EOF - End of File
  • STDIN/STDOUT/STDERR - Standard input/output/error
  • BASH - Bourne Again Shell
  • GNU - GNU's Not Unix
  • GPL - General Public License
  • OSS - Open Source Software
  • LTS - Long Term Support

Hardware & Boot

  • CPU - Central Processing Unit
  • RAM - Random Access Memory
  • BIOS - Basic Input/Output System
  • UEFI - Unified Extensible Firmware Interface
  • EFI - Extensible Firmware Interface
  • GRUB - Grand Unified Bootloader
  • MBR - Master Boot Record (2TB limit)
  • GPT - GUID Partition Table
  • GUID - Globally Unique Identifier
  • UUID - Universally Unique Identifier
  • HDD - Hard Disk Drive
  • SSD - Solid State Drive
  • SATA - Serial Advanced Technology Attachment
  • SCSI - Small Computer System Interface
  • IDE - Integrated Drive Electronics
  • PCI - Peripheral Component Interconnect
  • USB - Universal Serial Bus
  • I/O - Input/Output

File Systems & Storage

  • XFS - X File System (RHEL default)
  • EXT4 - Fourth Extended Filesystem
  • BTRFS - B-tree File System
  • ZFS - Zettabyte File System (not in RHEL)
  • LVM - Logical Volume Manager
  • PV - Physical Volume
  • VG - Volume Group
  • LV - Logical Volume
  • PE - Physical Extent
  • VDO - Virtual Data Optimizer
  • LUKS - Linux Unified Key Setup
  • RAID - Redundant Array of Independent Disks
  • NFS - Network File System
  • FSCK - File System Check
  • FDISK - Fixed Disk
  • SWAP - Swap Space

Networking

  • IP - Internet Protocol
  • IPv4 - Internet Protocol version 4
  • IPv6 - Internet Protocol version 6
  • TCP - Transmission Control Protocol
  • UDP - User Datagram Protocol
  • ICMP - Internet Control Message Protocol
  • DHCP - Dynamic Host Configuration Protocol
  • DNS - Domain Name System
  • BIND - Berkeley Internet Name Domain
  • HTTP - HyperText Transfer Protocol
  • HTTPS - HTTP Secure
  • FTP - File Transfer Protocol
  • SFTP - SSH File Transfer Protocol
  • SSH - Secure Shell
  • SSL - Secure Sockets Layer (deprecated)
  • TLS - Transport Layer Security
  • SMTP - Simple Mail Transfer Protocol
  • SNMP - Simple Network Management Protocol
  • CIDR - Classless Inter-Domain Routing
  • MAC - Media Access Control
  • ARP - Address Resolution Protocol
  • NAT - Network Address Translation
  • NIC - Network Interface Card
  • MTU - Maximum Transmission Unit
  • VLAN - Virtual Local Area Network
  • VPN - Virtual Private Network
  • WAN - Wide Area Network
  • DMZ - Demilitarized Zone
  • NMCLI - NetworkManager Command Line Interface
  • NMTUI - NetworkManager Text User Interface

Security

  • SELinux - Security-Enhanced Linux
  • MAC - Mandatory Access Control
  • DAC - Discretionary Access Control
  • RBAC - Role-Based Access Control
  • AVC - Access Vector Cache
  • MLS - Multi-Level Security
  • MCS - Multi-Category Security
  • PAM - Pluggable Authentication Modules
  • ACL - Access Control List
  • RSA - Rivest-Shamir-Adleman
  • SHA - Secure Hash Algorithm
  • MD5 - Message Digest 5
  • GPG - GNU Privacy Guard

Services & Process Management

  • SYSTEMD - System Daemon
  • PID - Process Identifier
  • PPID - Parent Process Identifier
  • PS - Process Status
  • RSS - Resident Set Size
  • CRON - Command Run On
  • NTP - Network Time Protocol
  • LDAP - Lightweight Directory Access Protocol
  • NIS - Network Information Service
  • IPC - Inter-Process Communication
  • FIFO - First In, First Out
  • LIFO - Last In, First Out

Containers & Virtualization

  • OCI - Open Container Initiative
  • VM - Virtual Machine
  • KVM - Kernel-based Virtual Machine
  • QEMU - Quick Emulator
  • VNC - Virtual Network Computing

Package Management

  • DNF - Dandified YUM
  • YUM - Yellowdog Updater Modified
  • RPM - Red Hat Package Manager
  • EPM - Enterprise Package Manager

Other Common Acronyms

  • AWK - Aho, Weinberger, and Kernighan
  • SED - Stream Editor
  • TAR - Tape Archive
  • REGEX - Regular Expression
  • CSV - Comma-Separated Values
  • HTML - HyperText Markup Language
  • XML - Extensible Markup Language
  • YAML - YAML Ain't Markup Language
  • JSON - JavaScript Object Notation
  • JVM - Java Virtual Machine
  • GCC - GNU Compiler Collection
  • LAMP - Linux, Apache, MySQL, PHP
  • RSYNC - Remote Sync
  • SAMBA - Server Message Block
  • UTF - Unicode Transformation Format
  • URI - Uniform Resource Identifier
  • URL - Uniform Resource Locator
  • WWW - World Wide Web
  • TUI - Text User Interface
  • TZ - Time Zone
  • ZLIB - Compression Library
  • KB - Kilobyte
  • MB - Megabyte
  • CD - Change Directory
  • DOS - Disk Operating System
  • ISO - International Organization for Standardization
  • HOME - Home Directory
  • PATH - Path Variable
  • SKEL - Skeleton
  • TMP - Temporary
  • UMASK - User Mask
  • GID - Group Identifier
  • UID - User Identifier
  • VI/VIM - Visual/Vi Improved
  • X11 - X Window System Version 11
  • PING - Packet Internet Groper

Key Non-Acronym Terms

System Components

  • daemon - Background service process
  • kernel - Core operating system component
  • shell - Command interpreter
  • terminal - Text interface for system access
  • console - Physical or virtual system interface

File System Terms

  • inode - Index node storing file metadata
  • block - Basic storage allocation unit
  • sector - Physical disk storage unit
  • mount - Attach filesystem to directory tree
  • umount - Detach filesystem from directory tree

Process Terms

  • fork - Create child process
  • exec - Execute new program
  • zombie - Defunct process awaiting cleanup
  • orphan - Process whose parent has terminated
  • thread - Lightweight process component

Network Terms

  • socket - Network communication endpoint
  • port - Network service identifier
  • interface - Network connection point
  • gateway - Network routing point
  • netmask - Network address mask

Security Terms

  • context - SELinux security label
  • boolean - SELinux policy toggle
  • permission - File access rights
  • capability - Fine-grained privilege
  • audit - Security event logging

Storage Terms

  • partition - Disk subdivision
  • filesystem - Data organization method
  • journal - Filesystem transaction log
  • quota - Storage usage limit
  • snapshot - Point-in-time copy

Service Terms

  • unit - Systemd management object
  • target - Systemd state grouping
  • service - Systemd daemon unit
  • timer - Systemd scheduled task
  • socket - Systemd activation unit

Container Terms

  • image - Container template
  • container - Running instance
  • registry - Image repository
  • namespace - Process isolation
  • cgroup - Resource control

This glossary covers essential acronyms and terms for RHCSA exam success. Review regularly to ensure familiarity with technical vocabulary.