| H081 | HFT | High-Frequency Trading | An automated trading system using powerful computers to transact large orders at extremely high speeds. | Financial markets and stock exchanges. |
| H082 | HFS | Hierarchical File System | A file system used by older Macintosh computers for data storage and retrieval. | Managing files in macOS Classic environments. |
| H083 | HGW | Home Gateway | A networking device that connects a local network to the internet. | Router used in smart home networks. |
| H084 | HIC | Head Injury Criterion | A measure used to assess the likelihood of head injury from an impact. | Crash test evaluations in automotive design. |
| H085 | HID | Human Interface Device | A type of computer device that interacts directly with humans. | Keyboards, mice, and game controllers. |
| H086 | HIL | Hardware-In-the-Loop | A simulation technique that tests hardware components within a virtual system environment. | Automotive control system validation. |
| H087 | HIM | Health Information Management | The practice of managing healthcare data for accuracy and accessibility. | Hospital electronic medical record systems. |
| H088 | HIPAA | Health Insurance Portability and Accountability Act | U.S. legislation ensuring privacy and security of medical information. | Compliance in electronic healthcare data management. |
| H089 | HIPS | Host Intrusion Prevention System | Software that monitors and blocks malicious activity on endpoints. | Enterprise endpoint cybersecurity solutions. |
| H090 | HLA | High-Level Architecture | A framework for distributed computer simulation systems. | Defense and aerospace simulation environments. |
| H091 | HLC | High-Level Controller | A control unit that manages overall process control in automation. | Industrial robotics system architecture. |
| H092 | HLR | Home Location Register | A database that stores subscriber information in mobile networks. | GSM and LTE telecommunication systems. |
| H093 | HMS | Hospital Management System | Software for managing administrative, financial, and clinical operations of hospitals. | Hospital IT infrastructure. |
| H094 | HMI | Human-Machine Interface | Interface allowing humans to interact with machines or systems. | Touchscreen control panels in industrial machinery. |
| H095 | HMM | Hidden Markov Model | A statistical model used in pattern recognition and speech processing. | Voice recognition software. |
| H096 | HNAC | Hybrid Network Access Control | Security system managing access to wired and wireless networks. | Enterprise IT environments. |
| H097 | HND | Higher National Diploma | Technical education qualification focused on practical skills. | Engineering and IT technical training programs. |
| H098 | HNDL | Handle | Reference to a system object or resource in computing. | File handles in Windows API programming. |
| H099 | HNS | Host Name System | Refers to naming systems for computers connected to networks. | Mapping hostnames to IP addresses. |
| H100 | HPC | High-Performance Computing | Computing systems with massive processing power for complex calculations. | Supercomputing in scientific simulations. |
| H101 | HPF | High-Pass Filter | An electronic filter that allows high-frequency signals to pass. | Audio engineering and signal processing. |
| H102 | HPI | Hardware Platform Interface | Defines the interface between management software and system hardware. | Server management and monitoring systems. |
| H103 | HPLC | High-Performance Liquid Chromatography | Analytical chemistry technique for separating mixtures. | Pharmaceutical compound testing. |
| H104 | HPM | High-Performance Module | A module designed for fast and efficient operations. | Embedded system architectures. |
| H105 | HPS | High-Pressure System | Engineering system operating under elevated pressure conditions. | Hydraulic and pneumatic systems. |
| H106 | HPU | Hydraulic Power Unit | Equipment generating and controlling hydraulic pressure. | Industrial manufacturing and automation. |
| H107 | HRAM | High-Resolution Analog Measurement | Precision analog data acquisition method. | Industrial sensors and metrology tools. |
| H108 | HRD | Human Resource Development | Training and education initiatives for workforce enhancement. | Corporate skill-building programs. |
| H109 | HRIS | Human Resource Information System | Software managing employee information and HR tasks. | HR analytics platforms in enterprises. |
| H110 | HRM | Human Resource Management | The process of recruiting, training, and managing workforce. | Employee performance tracking software. |
| H111 | HRMS | Human Resource Management System | Integrated platform automating HR activities. | Payroll and attendance tracking software. |
| H112 | HRS | Hydraulic Retardation System | System that controls vehicle deceleration hydraulically. | Heavy-duty trucks and buses. |
| H113 | HRT | Hardware Reliability Testing | Process ensuring hardware operates under required conditions. | Stress and environmental testing of devices. |
| H114 | HRU | Heat Recovery Unit | Equipment that captures and reuses waste heat energy. | HVAC systems in energy-efficient buildings. |
| H115 | HSC | High-Speed Controller | Microcontroller designed for high-speed data operations. | Real-time automation processes. |
| H116 | HSD | High-Speed Data | Broadband technology providing rapid data transmission. | Cellular and satellite internet systems. |
| H117 | HSF | High-Strength Fiber | Material engineered for exceptional tensile strength. | Aerospace composites. |
| H118 | HSM | Hardware Security Module | Dedicated device for secure key management. | Banking encryption systems. |
| H119 | HSO | Hosted Service Offering | Cloud service delivered via internet-based infrastructure. | SaaS and PaaS solutions. |
| H120 | HSS | High-Speed Steel | Alloy steel used in cutting tools for high-speed machining. | Lathe and drill manufacturing. |
| H121 | HTML | HyperText Markup Language | Standard coding language for web page structure. | Website development. |
| H122 | HTTP | HyperText Transfer Protocol | Protocol for transferring web data between servers and browsers. | Browsing internet websites. |
| H123 | HTTPS | HyperText Transfer Protocol Secure | Secure version of HTTP using encryption. | Secure online transactions. |
| H124 | HVAC | Heating, Ventilation, and Air Conditioning | System for regulating indoor environmental comfort. | Building climate control systems. |
| H125 | HVD | High-Voltage Direct | Refers to direct current operating at high voltage. | Power transmission in industrial systems. |
| H126 | HVE | High-Voltage Engineering | Field studying electrical systems with high voltage. | Power grid and insulation design. |
| H127 | HVR | High-Voltage Relay | Electrical relay for switching high-voltage circuits. | Power distribution networks. |
| H128 | HVS | Human Visual System | Physiological system responsible for visual perception. | Computer vision modeling. |
| H129 | HWL | Hardware Layer | Physical component layer in computing architecture. | Network hardware abstraction. |
| H130 | HWR | Hardware Resource | Physical computing resource used by software systems. | CPU, GPU, and memory in computing devices. |
| H131 | HWS | Hardware Security | Measures ensuring hardware-level system protection. | Tamper-proof embedded devices. |
| H132 | HX | Heat Exchanger | Device transferring heat between fluids without mixing them. | Power plants and HVAC systems. |
| H133 | HYB | Hybrid System | System combining two different technologies for performance. | Hybrid electric vehicles. |
| H134 | HZ | Hertz | Unit of frequency representing one cycle per second. | Measuring AC power frequency. |
| H135 | HZO | Hybrid Zinc Oxide | Semiconductor material used in sensors and electronics. | Solar cells and gas sensors. |
| H136 | HZD | Hazard Detector | Device used to detect environmental or electrical hazards. | Fire and gas detection systems. |
| H137 | HZI | Hazard Identification | Process for detecting potential workplace hazards. | Industrial safety inspections. |
| H138 | HZS | Hazardous Substances | Substances posing risk to health or the environment. | Chemical handling in labs. |
| H139 | HZT | Hazard Zone Temperature | Maximum temperature allowed in hazardous zones. | Oil and gas explosion prevention. |
| H140 | HZV | Hazard Voltage | Dangerous voltage level potentially causing electric shock. | Electrical safety testing. |
| H141 | HSSP | High-Speed Signal Processing | Processing of data signals at high transmission rates. | Radar and communication systems. |
| H142 | HDSL | High-Bit-Rate Digital Subscriber Line | DSL technology enabling high-speed internet over copper lines. | Telecommunications infrastructure. |
| H143 | HBA | Host Bus Adapter | Hardware interface connecting computers to storage networks. | Fibre Channel and SCSI devices. |
| H144 | HBM | High Bandwidth Memory | Advanced memory technology with high data transfer rates. | GPUs and high-performance computing. |
| H145 | HBC | High Breaking Capacity | Electrical device capable of interrupting high fault currents. | Circuit breakers. |
| H146 | HBF | Heat Balance Factor | Ratio used to measure heating system performance. | Thermal analysis in building design. |
| H147 | HBI | Host-Based Intrusion | Security mechanism detecting unauthorized activities on hosts. | Intrusion detection software. |
| H148 | HBMV | High Bandwidth Multi-View | Imaging system enabling multiple high-speed perspectives. | 3D visualization systems. |
| H149 | HBT | Heterojunction Bipolar Transistor | High-speed semiconductor transistor using different materials. | RF amplifiers and high-frequency circuits. |
| H150 | HBR | High Bit Rate | Data transmission rate that supports high data volume. | HD video streaming technology. |
| H151 | HCD | Human-Centered Design | Design process prioritizing user experience and usability. | UX/UI product development. |
| H152 | HCF | Hollow Core Fiber | Optical fiber with air-filled core for minimal light loss. | High-speed telecommunications. |
| H153 | HCO | Hydraulic Control Operator | Technician managing hydraulic systems. | Industrial plant maintenance. |
| H154 | HCP | High-Current Protection | Protection system for managing high electrical currents. | Power system design. |
| H155 | HCS | Hardware Control System | System for managing and controlling physical hardware. | Automated manufacturing systems. |
| H156 | HCT | Hardware Compatibility Test | Process ensuring new hardware operates with existing systems. | Quality assurance in computer assembly. |
| H157 | HDA | High Definition Audio | Standard ensuring high-quality audio playback on PCs. | Sound cards and audio interfaces. |
| H158 | HDB | High Density Board | PCB with tightly packed electronic components. | Compact smartphone and IoT devices. |
| H159 | HDLC | High-Level Data Link Control | Protocol ensuring reliable data transmission. | Networking and telecommunications. |
| H160 | HDP | Hardware Design Process | Structured process of developing hardware products. | Semiconductor design workflow. |
| H161 | HDR | High Dynamic Range | Imaging technology that enhances contrast and brightness. | Photography and TV displays. |
| H162 | HDS | High Density Storage | Compact, high-capacity data storage technology. | Data centers and cloud servers. |
| H163 | HEV | Hybrid Electric Vehicle | Vehicle combining internal combustion and electric power. | Toyota Prius and similar models. |
| H164 | HET | Heat Exchanger Tube | Component in a heat exchanger facilitating heat transfer. | HVAC and power systems. |
| H165 | HEX | Hexadecimal | Base-16 numeral system used in computing. | Memory address representation. |
| H166 | HGA | Head Gimbal Assembly | Component positioning read/write head in hard drives. | HDD manufacturing. |
| H167 | HGT | High-Grade Transformer | Transformer with superior insulation and core materials. | Industrial power distribution. |
| H168 | HICV | High-Intensity Control Valve | Valve designed for extreme pressure or flow conditions. | Oil and gas processing plants. |
| H169 | HIE | Health Information Exchange | Platform for secure sharing of healthcare data. | Hospital interoperability systems. |
| H170 | HIMT | Heat Integration Modeling Tool | Software for simulating heat recovery and process optimization. | Chemical engineering analysis. |
| H171 | HIP | High-Impact Plastic | Plastic material resistant to shock and deformation. | Helmet or automotive body parts. |
| H172 | HIRF | High-Intensity Radiated Fields | Strong electromagnetic fields affecting electronic systems. | Aircraft electromagnetic compatibility testing. |
| H173 | HLAE | High-Level Application Environment | Software environment for running advanced apps. | Distributed computing frameworks. |
| H174 | HLB | Hydrophilic-Lipophilic Balance | Ratio indicating surfactant solubility. | Formulation of emulsions in cosmetics. |
| H175 | HLN | High-Level Network | Advanced network model handling complex protocols. | Data center network management. |
| H176 | HLO | High-Level Optimization | Algorithm improving computational performance. | Compiler optimization process. |
| H177 | HLP | High-Level Protocol | Communication protocol operating at application layers. | HTTP and FTP implementations. |
| H178 | HLS | Hardware Logic Synthesis | Process of converting hardware design to logic gates. | FPGA development. |
| H179 | HLT | Hardware Load Test | Stress test for evaluating system reliability. | Hardware QA process. |
| H180 | HMC | Hybrid Memory Cube | High-speed 3D memory architecture. | Advanced computing and GPUs. |
| H181 | HMD | Head-Mounted Display | Wearable display for virtual or augmented reality. | VR gaming and simulation. |
| H182 | HMIoT | Human-Machine Internet of Things | Integration of IoT with human–machine interfaces. | Smart manufacturing dashboards. |
| H183 | HMSL | Hybrid Multi-Sensor Layer | Combination of multiple sensors for data fusion. | Robotics and autonomous systems. |
| H184 | HMW | High Molecular Weight | Describes polymers with long molecular chains. | Industrial-grade polyethylene production. |
| H185 | HNC | Hybrid Numerical Control | Computer control combining digital and manual modes. | CNC machining. |
| H186 | HND | Higher National Diploma | UK-based vocational qualification. | Technical engineering studies. |
| H187 | HNP | Host Negotiation Protocol | USB protocol defining device role exchange. | USB OTG (On-The-Go) communications. |
| H188 | HOC | High-Order Computing | Computational techniques solving large-scale problems. | Scientific and climate modeling. |
| H189 | HOE | High-Output Engine | Engine producing power above standard ratings. | Performance vehicles and generators. |
| H190 | HOL | Hardware Object Layer | Abstraction layer managing hardware objects. | Embedded system software design. |
| H191 | HOM | Heat Output Measurement | Measuring total heat produced by a system. | Power plant thermal efficiency testing. |
| H192 | HON | Hybrid Optical Network | Network integrating optical and traditional connections. | Data transmission infrastructure. |
| H193 | HOS | Hours of Service | Regulations governing work hours of commercial drivers. | Fleet compliance tracking. |
| H194 | HOV | High Occupancy Vehicle | Lane reserved for vehicles with multiple passengers. | Highway traffic management. |
| H195 | HPD | Hearing Protection Device | Equipment that reduces sound exposure to safe levels. | Earplugs used in factories. |
| H196 | HPE | High-Performance Engine | Engine designed for superior speed and torque. | Sports cars and aircraft. |
| H197 | HPFET | High Power Field Effect Transistor | Transistor handling large currents or voltages. | RF amplifiers and power supplies. |
| H198 | HPMS | Highway Performance Monitoring System | System for collecting data on road use and conditions. | U.S. Department of Transportation analytics. |
| H199 | HPP | High Pressure Pump | Device moving fluids under high pressure. | Hydraulic and fuel injection systems. |
| H200 | HPUX | Hewlett-Packard UNIX | Operating system developed by HP for servers. | Enterprise-grade UNIX computing. |