Certified - CompTIA Server+

Welcome to The Bare Metal Cyber Server Plus Prepcast. This series helps you prepare for the exam with focused explanations and practical context.
In this episode, we continue our glossary journey by exploring key Server Plus acronyms from the letters H through O. These terms focus heavily on hardware infrastructure, server management, virtualization, and operating system fundamentals. Many of these acronyms appear across multiple domains in the exam, especially in performance-based questions and real-world troubleshooting scenarios.
Host Bus Adapter, or H B A, is a hardware component that connects a server to external storage networks, most commonly Storage Area Networks. It acts as a bridge between the system and fiber channel or S A S storage systems, handling data transmission at high speed. Understanding H B A configuration is essential when setting up shared storage or managing disk arrays in enterprise environments.
Hardware Compatibility List, or H C L, is a reference document or database that identifies which hardware components are officially supported by a particular operating system. Before deploying an operating system to new hardware, system administrators consult the H C L to verify that chipsets, drives, and controllers will work reliably. Using unsupported components can lead to installation failures or post-deployment issues that complicate server performance.
Integrated Lights-Out, Dell Remote Access Controller, and Intelligent Platform Management Interface—known respectively as I L O, I D R A C, and I P M I—are all technologies that provide out-of-band remote management capabilities. These tools allow administrators to monitor system health, restart servers, or access consoles even when the main operating system is down. They are essential for managing servers in remote data centers where physical access may be limited or delayed.
Heating, Ventilation, and Air Conditioning, or H V A C, refers to the systems that regulate temperature and airflow in server rooms and data centers. Servers generate significant heat, and without proper cooling, they can throttle performance, crash, or suffer hardware damage. Administrators must monitor H V A C systems as part of their environmental control strategy, ensuring temperature thresholds are maintained and airflow is not obstructed.
Graphics Processing Unit, or G P U, is a specialized chip designed to accelerate image rendering, video decoding, and increasingly, compute workloads. While G P Us were originally used for visual applications, they now play an important role in servers that support artificial intelligence, machine learning, and virtual desktop infrastructure. Many modern servers include one or more G P Us to offload computational tasks from the central processor.
Keyboard Video Mouse switch, or K V M, allows administrators to control multiple computers using a single keyboard, display, and mouse. These switches are common in rack environments where space is limited. I P K V M adds the ability to access these systems over a network, providing remote keyboard and screen control even if the server is offline or experiencing boot issues.
Liquid Crystal Display and Light Emitting Diode—abbreviated as L C D and L E D—are display technologies used in monitoring panels, diagnostic screens, and rack-mounted server consoles. These displays show real-time status indicators, including system temperatures, error codes, and initialization messages. While they may seem minor, understanding how to read L C D and L E D outputs is important when physically inspecting or diagnosing server behavior.
Uninterruptible Power Supply, or U P S, is a device that provides emergency power to servers in the event of electrical failure. It allows enough time to save data, shut down systems, or switch to backup generators. Power Distribution Unit, or P D U, is used to distribute power to multiple systems within a rack and often includes monitoring functions. Together, the U P S and P D U ensure consistent and reliable power delivery, reducing the risk of unexpected shutdowns.
Host Intrusion Detection System and Host Intrusion Prevention System—known as H I D S and H I P S—are security tools installed directly on servers. A H I D S monitors the system for suspicious activity, such as unauthorized file changes or unexpected traffic. A H I P S takes this further by actively blocking or responding to threats. These systems work at the host level and complement broader network security efforts.
Intrusion Detection System and Intrusion Prevention System, or I D S and I P S, are similar in function but operate at the network level. An I D S monitors network traffic for malicious patterns or unusual activity and logs those events. An I P S not only detects but also blocks the activity in real time, based on predefined rules. These tools are often used in tandem with host-based systems to create layered defense strategies.
Access Control List, or A C L, which we covered previously, also appears again here under access control. It defines permissions for files, services, or devices, specifying who can read, write, or execute a given resource. A C Ls are foundational in securing both physical and virtual assets.
Terminal Access Controller Access Control System and Remote Authentication Dial-In User Service—known as T A C A C S and R A D I U S—are authentication protocols used in large-scale networks. T A C A C S is more flexible in separating authentication and authorization processes, while R A D I U S is lightweight and widely supported. Both are used for centralized login management, especially on routers, switches, and wireless controllers.
Security-Enhanced Linux, or S E Linux, is a kernel-level security feature that enforces strict access control policies. It uses a concept known as mandatory access control to define what actions processes can perform, limiting what even root users can do. S E Linux is common in high-security Linux environments where granular control is essential for system hardening.
Internet Information Services, or I I S, is Microsoft’s built-in web server software. It allows Windows-based systems to host websites, applications, and services such as F T P or web applications using A S P dot N E T. I I S includes management tools for configuring application pools, access control, and performance logging.
Microsoft Management Console, or M M C, is a framework that allows administrators to manage system components through modular snap-ins. Each snap-in represents a different administrative tool, such as disk management or user administration. M M C provides a unified interface for performing a wide range of system tasks, particularly on Windows servers.
Simple Network Management Protocol, or S N M P, allows administrators to monitor network devices and servers by polling status data and receiving alerts. It uses a management information base to define what data can be accessed. S N M P is critical for server monitoring platforms and automated alert systems, especially in larger infrastructure environments.
Windows Management Instrumentation and its command-line tool W M I C provide access to system information and administrative functions in Windows environments. W M I is used by administrators and scripts to collect data such as disk usage, installed software, and service states. These tools are especially useful for automation and remote server management.
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Internet Protocol Security, or I P S E C, is a suite of protocols designed to encrypt and authenticate data at the network layer. It can operate in transport mode, which secures only the payload of a packet, or tunnel mode, which secures the entire packet including the header. I P S E C is used in virtual private networks and site-to-site connections to ensure that data remains private and unaltered during transmission over untrusted networks.
Internet Small Computer System Interface, or I S C S I, is a protocol that enables block-level storage access over a network. It allows servers to communicate with storage devices using standard I P networking, removing the need for dedicated storage cabling. Administrators use I S C S I to build flexible and cost-effective storage area networks that scale well with server deployments.
Small Computer System Interface, or S C S I, is a legacy set of standards for connecting and transferring data between servers and peripheral devices. Serial Attached S C S I, or S A S, is a modern implementation that uses point-to-point signaling for faster speeds and improved reliability. Serial A T A, or S A T A, is another common interface used for connecting hard drives and solid state drives, especially in entry-level or consumer-grade systems. Non-Volatile Memory Express, or N V M E, is the newest and fastest among these technologies, offering direct communication between the drive and the processor over the P C I Express bus.
Operating System, or O S, is the software that manages all hardware and software resources on a server. It handles memory allocation, task scheduling, input and output management, and user interactions. Common server operating systems include Windows Server, various Linux distributions, and Unix-based platforms, each offering different capabilities for roles like file sharing, domain control, and web hosting.
Network Operating System, or N O S, is an operating system specifically designed to manage network resources, directory services, and user permissions across multiple systems. While the term has become less common, it traditionally referred to systems like Novell NetWare or early versions of Windows Server. The main function of a N O S is to enable resource sharing, centralized control, and secure communication across a domain.
Original Equipment Manufacturer, or O E M, refers to a company that produces hardware or software components which are then branded or resold by another vendor. In the server world, O E M licenses often include pre-installed operating systems or management tools. Understanding O E M designations is important when purchasing or maintaining servers, as licensing terms and support channels may differ from retail versions.
Hyper V is Microsoft’s native virtualization platform, used to create and manage virtual machines on Windows systems. It allows administrators to run multiple operating systems on a single physical host, allocate resources like memory and processor time, and create isolated environments for testing or production use. Hyper V includes features like snapshotting, replication, and integration with cloud services, making it suitable for both small and large-scale deployments.
Virtualization Technology, or V T, refers to hardware-level support built into modern processors that enhances the performance and security of virtual machines. V T enables better isolation, faster context switching, and access to advanced features like nested virtualization. It is typically enabled or disabled through the system firmware and must be supported by the server’s C P U to use advanced hypervisors.
Virtual Network Computing, or V N C, is a protocol that allows remote desktop sharing by transmitting screen updates and keyboard or mouse inputs over the network. It enables administrators to interact with servers as if they were physically present, even when operating in headless or remote environments. V N C is widely used for remote troubleshooting, support, and monitoring, especially in mixed platform networks.
Virtual Machine, or V M, refers to a software-based emulation of a physical computer. It runs an operating system and applications just like a physical system but is isolated and hosted within a hypervisor. V Ms are essential for modern server environments because they allow resource consolidation, flexible provisioning, and easier disaster recovery.
Virtual Machine File System, or V M F S, is a high-performance clustered file system developed by VMware. It allows multiple virtual machines to share the same storage while maintaining data consistency and isolation. V M F S is often used in environments that require high availability, centralized management, and integration with backup or snapshot technologies.
Virtual Network Interface Card, or V N I C, is a software-defined network adapter used inside a virtual machine. It connects the V M to the virtual switch and provides network access through the host system’s physical adapter. Multiple V N I Cs can be assigned to a single virtual machine, allowing it to operate across different networks or be configured for fault tolerance.
Virtual Local Area Network, or V L A N, is a logical segmentation of a physical network. It groups devices together even if they are not on the same physical switch, providing isolation and improved traffic control. V L A Ns are commonly used to separate systems by function, such as isolating servers, storage, and user devices for both security and performance optimization.
Physical to Virtual, or P two V, refers to the process of converting a physical server into a virtual machine. This involves capturing the system image, including the operating system, drivers, and data, and then importing it into a virtual environment. P two V is commonly used during data center migrations, system upgrades, or to consolidate legacy infrastructure into modern virtual platforms.
All of these acronyms—from H B A to P two V—form the technical foundation of the Server Plus vocabulary. Understanding them in context allows you to navigate configuration menus, interpret log files, troubleshoot problems, and pass simulation questions with confidence. These are not just letters on a screen. They represent key ideas that appear repeatedly in server documentation, training materials, and production environments.
In the next episode, we continue our glossary series by exploring acronyms from the letters P through Z. These will include backup formats, cloud models, network protocols, and security enforcement systems. Mastering the full Server Plus glossary builds the confidence and fluency needed for both certification and job performance.