Network and Systems Administration Glossary

A Microsoft directory service for Windows domain networks that provides centralized identity management, authentication via Kerberos, and Group Policy enforcement.

An open-source automation tool that uses agentless architecture and YAML playbooks to manage configuration, deployment, and orchestration across servers.

The inter-domain routing protocol that exchanges routing information between autonomous systems on the internet, enabling global connectivity.

A method for allocating IP addresses and routing that replaces the older classful addressing system, using variable-length subnet masks denoted with slash notation (e.g., /24).

A lightweight, portable, self-sufficient unit that packages an application with all its dependencies, sharing the host operating system kernel for efficient resource usage.

Dynamic Host Configuration Protocol, a network protocol that automatically assigns IP addresses and other configuration parameters to devices joining a network.

A perimeter network segment that sits between an internal trusted network and an external untrusted network, hosting public-facing services like web and mail servers.

Domain Name System, a hierarchical distributed naming system that translates human-readable domain names into IP addresses used for network communication.

The automatic switching of operations from a failed system or component to a standby redundant system, ensuring continued service availability with minimal interruption.

A network security system that monitors and controls incoming and outgoing traffic based on predetermined rules, serving as a barrier between trusted and untrusted networks.

A feature of Windows Active Directory that allows administrators to define and enforce security settings, software installation, and user configurations across all domain-joined computers.

Software that creates and manages virtual machines by abstracting physical hardware resources. Type 1 runs on bare metal; Type 2 runs on a host operating system.

The practice of defining and managing computing infrastructure through machine-readable configuration files, enabling version control, automation, and repeatable deployments.

Lightweight Directory Access Protocol, an open standard for accessing and maintaining distributed directory information services over a TCP/IP network.

A device or software that distributes incoming network traffic across multiple servers to ensure reliability, availability, and optimal performance of applications.

A method of remapping private IP addresses to a public address for internet communication, conserving IPv4 address space and masking internal network structure.

A protocol for synchronizing clocks of computer systems over packet-switched networks, critical for log correlation, authentication protocols, and scheduled tasks.

The seven-layer Open Systems Interconnection reference model that standardizes communication functions: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

Redundant Array of Independent Disks, a technology combining multiple physical drives into a logical unit for improved performance, redundancy, or both.

Simple Network Management Protocol, used to collect information from and configure network devices, enabling centralized monitoring and management of infrastructure.

Secure Shell, a cryptographic protocol for secure remote access, file transfer, and tunneling over unsecured networks, replacing insecure protocols like Telnet.

A logically defined subdivision of an IP network, created by applying a subnet mask to partition a larger network into smaller, more manageable segments.

Transmission Control Protocol, a connection-oriented transport layer protocol that provides reliable, ordered, and error-checked delivery of data between applications.

Virtual Local Area Network, a logical grouping of devices on different physical LAN segments into a single broadcast domain, improving security and reducing broadcast traffic.

Virtual Private Network, a technology that creates an encrypted tunnel over a public network to securely extend a private network, enabling remote access and site-to-site connectivity.