H
* Handshaking
* Handwriting Recognition
* Hard Disk
* Hard Disk Drive
* Hard Disk Partition
* Hardware
* Hardware Handshake
* Hardware Monitor
* Hardware Platform
* HDD Unit: Hard Disk Drive Unit
* HDTV: High Definiton Television
* Headless server
* Heat Sink
* High Definition
* HIPPI: High Performance Parallel Interface
* HMD: Head-Mounted Display
* Host Bus
* HBA: Host Bus Adaptor
* Host-Based Modem
* Hot plug
* HPA: High-Performance Addressing
* Hub
* Hyper-Threading
* HyperTransport
handshaking
In the context of computers, handshaking indicates hardware or software to establish or maintain two machines or programs in synchronisation. Handshaking often requires the exchange of messages or packets of data between two systems. Hardware handshaking signals between two computers which are carried by voltage levels or pulses on wires. There are many handshaking protocols for software handshaking. Basically, the handshaking protocol send a "hello" message to the receiving system and get a "ok" responce. When the communication between the two systems finished, a "finish" message should be send and confirmed by both systems.
handwriting recognition
Handwriting recognition refers to a computer receiving handwritten input and intelligently recognize it to some characters. The image of the written text may be sensed "off line" from a piece of paper by optical scanning (optical character recognition). Alternatively, the movements of the pen tip may be sensed "on line", for example by a pen-based computer screen surface.
hard disk
A hard disk is a non-volatile data storage device that stores data on a magnetic surface layered onto hard disk platters.
hard disk drive
Hard disk drive, also known as hard drive or hard disk, is a magnetic disk to store computer data. A hard disk uses rigid rotating platters (disks). It stores and retrieves digital data from a planar magnetic surface. Information is written to the disk by transmitting an electromagnetic flux through an antenna or write head that is very close to a magnetic material, which in turn changes its polarization due to the flux. The information can be read back in a reverse manner, as the magnetic fields cause electrical change in the coil or read head that passes over it.
Hard Disk Partition
Hard disk partition refers to the creation of logical divisions upon a hard disk that allows one to apply operating system-specific logical formatting. Disk partitioning is a simple technique which can be viewed as a precursor of Logical volume management. Partitioning allows one to have multiple file-systems on a single hard disk.
hardware
In computer field, hardware indicates all of the physical parts of a computer, as distinguished from the data it contains or operates on, and the software that provides instructions for the hardware to accomplish tasks. The boundary between hardware and software is slightly blurry. For example, firmware is software that is "built-in" to the hardware. Firmware is usually the province of computer programmers and computer engineers in any case and not an issue that computer users need to concern themselves with. Computer hardware typically consists chiefly of electronic devices (CPU, memory, display) with some electromechanical parts(keyboard, printer, disk drives, tape drives, loudspeakers) for input, output, and storage, though completely electronic (mechanical,electromechanical, hydraulic, biological) computers have also been conceived of and built.
hardware handshake
In the context of networking, hardware handshake refers to establish or maintain two machines in synchronisation. Handshaking often requires the exchange of messages between two systems. Hardware handshaking signals between two computers which are carried by voltage levels or pulses on wires. When the communication between the two systems finished, a "finish" message should be send and confirmed by both systems.
hardware monitor
Hardware monitor is a device that monitors the hardware circuits of a computer for the purpose of checking the performance of the system.
hardware platform
Hardware platform within the computer industry refers to the type of hardware configuration required to process the applications software product. Each hardware platform has its own operating system such as UNIX, IBM AS/400 etc., and all software used by it must use that OS. Therefore, the term is also sometimes extended to Operating System.
HDD Unit: Hard Disk Drive Unit
Hard Disk Drive Unit (HDD unit) contains two hard drives for storing the database and the software.
HDTV: High Definiton Television
High Definiton Television (HDTV), introduced by the Digital HDTV Grand Alliance, refers to the broadcasting of television signals with a higher resolution than traditional formats (NTSC, SECAM, PAL) allow. HDTV is defined as 1080 active interlaced or progressive lines, or 720 progressive lines. 16 : 9 aspect ratio in ITU-R BT.709. The term "high-definition" can refer to the resolution specifications themselves, or to media capable of similar sharpness such as movie film. Except for early analog formats in Europe and Japan, HDTV broadcasts digitally.
Headless server
Headless server is a server without a keyboard, monitor, or mouse.
heat sink
Heat sink is a metal base or plate onto which one or more components are mounted to absorb, carry away, or radiate the heat generated by the component(s). Heat sinks are generally made of an aluminum alloy and often have fins. All computers require a heat sink. Some also require a fan. A heat sink without a fan is called a passive heat sink; a heat sink with a fan is called an active heat sink.
High Definition
High Definition is a video format consisting of withering 720p (active lines of progressive ) or 1080 which could be either active lines of progressive, 1080p, or interlaced, 1080i.
HIPPI: High Performance Parallel Interface
High Performance Parallel Interface (HIPPI) is computer bus to connect devices at short distances with high speeds. It was popular in the late 1980s and into the mid-to-late 1990s, but has since been replaced by ever-faster standard interfaces like SCSI and Fibre Channel.
HMD: Head-mounted display
Head-mounted display (HMD) is a headset used with virtual reality systems. The HMD usually consists of either a helmet or glasses with either one or two small LCD or OLED displays with magnifying lenses, one for each eye. The technology can be used to show stereo 3D films, stereoscopic images or interactive 3D games. Head-mounted displays may also be coupled with head-tracking devices to allow the user "look around" a virtual reality environment naturally by moving the head without the need for a separate controller.
host bus
Host bus, also known as Front-Side-Bus (FSB), CPU bus, memory bus and system bus, is the bus between Processor (CPU) to system memory. The front side bus on a computer connects the processor to the north side bridge, which comprises the memory bus, PCI bus and AGP bus. In general, a faster frontside bus means higher processing speeds and a faster computer.
HBA: Host Bus Adaptor
Host Bus Adapter (HBA), also known as host adaptor, connects the computer with other network and storage devices. The terms are primarily used to refer to devices for connecting Fibre Channel and SCSI devices, but devices for connecting to ESCON, Ethernet, and other systems may also be called host adapters. Recently, the advent of iSCSI has brought about Ethernet HBAs, some including TCP Offload Engines.
host-based modem
Host based modem relies on the CPU in a computer to perform some of the communications processing. A modem that uses the computer's processor to handle some operations. Host-based modems are less expensive than conventional modems. There are also software modems, in which there's no modem device at all. Instead, all of the modem's functions are handled by the computer's processor.
hotplug
Hotplug, also known as hot swapping, is the ability to remove and replace components of a machine, usually a computer, while it is operating. The operating system automatically recognizes the change. Once the appropriate software is installed on the computer, one can plug and unplug the device without rebooting. Two external bus standards -- Universal Serial Bus (USB ) and IEEE 1394 -- support hot plugging. This is also a feature of PCMCIA.
HPA: High-Performance Addressing
High-Performance Addressing (HPA) is an passive-matrix display technology the provides better response rates and contrast than conventional LCD displays. Although HPA displays aren't quite as crisp or fast as active-matrix (TFT) displays, they're considerably less expensive to produce.
Hub
The Hub, also called repeater, is a device that accepts Ethernet connections from network devices and cross-connects them. Data arriving via the receive pair of one connection is regenerated and sent out on the transmit pair to all connected devices except for the device who originated the transmission
Hyper-Threading
Hyper-Threading, developed by Intel, enables multithreaded software applications to execute threads in parallel on a single multi-core processor instead of processing threads in a linear fashion. Hyper-Threading Technology (HTT) is implemented on the Pentium 4 microarchitecture. It is basically a more advanced form of Super-threading that first debuted on the Intel Xeon processors and was later added to Pentium 4 processors. The technology improves processor performance under certain workloads by providing useful work for execution units that would otherwise be idle, for example during a cache miss.
HyperTransport
HyperTransport (HT), formerly known as Lightning Data Transport (LDT), is a bidirectional serial/parallel high-bandwidth, low-latency computer bus. HyperTransport runs at 200-1400 MHz (compared to PCI at either 33 or 66 MHz). It is also a DDR or "Double pumped" bus, meaning it sends data on both the rising and falling edges of the 1400 MHz clock signal. This allows for a maximum data rate of 2800 MTransfers/s per pair. The frequency is auto-negotiated.