cellular radio
A component in a mobile device that is capable of switching frequencies automatically when moving between network cells without losing the connection.
DVD
(Digital Video/Versatile Disc) An optical storage technology. DVDs offer higher capacities (4.7 GB per layer) than the preceding CD-ROM format. As with CDs, recordable and re-writable forms of DVD exist, though there are numerous competing formats (notably +/-R and +/-RW and DVD-RAM).
pits
In optical storage media, recessed areas on the disk.
*aaS
(Something as a Service) An ownership model for cloud services where "something" can refer to infrastructure, network, platform, or software
3D modeling software
Software that creates a model of physical objects using polygons, spline curves and bezel curves
3d print process
A printing process that builds a solid object from successive layers of material
3d printer
Hardware device capable of small scale manufacturing. 3D printers use a variety of filament media (typically plastic) with different properties.
3D scanner
A scanner that can gather data about the shape and appearance of a phsyical object and save that information to a computer
3D slicing software
Software in a 3D printer or in 3D modeling software that takes a 3D model and creates multiple horizontal layers of the model
802.3af
PoE powered devices can draw up to about 13 W over the link. Power is supplied as 350mA@48V and limited to 15.4 W, but the voltage drop over the maximum 100 feet of cable results in useable power of around 13 W.
802.3at (PoE+)
PoE powered devices can draw up to about 25 W. PoE+ allows for a broader range of devices to be powered such as cameras with pan/tilt/zoom capabilities , door controllers, and thin client computers.
AC
(alternating current) When electricity is produced by a generator at the power station, the rotational movement of the magnetic coils causes the current produced to oscillate like a sine wave (it is said to alternate). Computers require direct current (at a constant voltage). A transformer is used to convert AC from the power outlet into the 3.3, 5, and 12 V DC supply required by the computer
AC adapter
An external power supply used to power laptops and other portable devices
accelerometer
Mobile technology that can determine the orientation of a device with a sensor that measures the acceleration of device direction
Accelerometer / Gyroscope
Components used in mobile devices to detect motion (accelerometer) and rotation (gyroscope). As well as switching screen orientation, this can be used as a control mechanism (for example, a driving game could allow the tablet itself to function as a steering wheel).
access time
The speed at which memory or a disk drive can be addressed and utilized (opened, read from, or written to).
ACL
(Access Control List) The permissions attached to or configured on a network resource, such as a folder, file, or firewall. The ACL specifies which subjects (user accounts, host IP addresses, and so on) are allowed or denied access and the privileges given over the object (read only, read/write, and so on)
ad-hoc mode
A temporary network mode in which devices connect to each other directly without an intermediary networking device
ad-hoc network
A peer-to-peer network created for the current print session.
adapter card
Circuit board providing additional functionality to the computer system (video, sound, networking, modem, and so on). An adapter card fits a slot on the PC's expansion bus and often provides ports through slots cut into the back of the PC case. Different cards are designed for different slots (PCI or PCie).
add-on card
An adapter card installed in a PCIe slot
additive color printing
A color printing method that combines differently colored transmitted light to form different shades.
ADF
(Auto Document Feeder) Device that feeds media automatically into a scanner or printer
ADSL
(Asymmetrical DSL) A consumer version of DSL that provides a fast downlink but a slow uplink. The upstream rate is between 64 Kbps and 1 Mbps and the downstream rate is 500 Kbps to 8 Mbps
Android application package
(APK) Third-party or custom programs that are installed directly through an APK file, giving users and businesses the flexibility to install apps directly on Android devices.
autodiscover
The ability of a mobile device to determine connection settings based on the user entering their email credentials.
COM port
(communications port) Windows' representation of a computer's serial port(s), numbered sequentially (COM1, COM2...).
developer roller
A magnetized roller to which toner adheres during the printing process.
I/O port
A device connection through which data can be sent and received.
LGA
(Land Grid Array) A CPU form factor used by Intel where the pins that connect the CPU and socket are located on the socket.
MIB
(Management Information Base) A database used by SNMP in which agents maintain configuration and usage data and identifies what information the managed system offers.
overclocking
Manually setting the CPU and chipset to run at a faster speed than advised by the manufacturer. Some CPUs are better suited to overclocking than others and the system will generally need a better cooling system to cope with the increased thermal output.
PAN
(Personal Area Network) Close range networking (usually based on Bluetooth or NFC) allowing communications between personal devices, such as smartphones, laptops, and printers/peripheral devices.
passive cooling device
A CPU generates a large amount of heat that must be dissipated to prevent damage to the chip. Generally, a CPU will be fitted with a heatsink (a metal block with fins) and fan. Thermal compound is used at the contact point between the chip and the heatsink to ensure good heat transfer. The PSU also incorporates a fan to expel warm air from the system. Modern motherboards have temperature sensors that provide warning of overheating before damage can occur. Very high performance or overclocked systems or systems designed for quiet operation may require more sophisticated cooling systems, such as liquid cooling. Cooling systems that work without electricity are described as passive; those requiring a power source are classed as active.
QR codes
(Quick Response codes) A 2D barcode created of black and white squares used to store information that can be read using a barcode scanner or the camera on a smartphone that has a barcode scanning app installed
RTC
(Real Time Clock Battery) The battery that powers the chipset that keeps track of date and time for the system.
semiconductor
A material that can act as both a conductor and an insulator, which provides switch-like functionality, where a circuit can be opened and closed, used to represent binary (on/off) digits.
SODIMM
(Small Outline Dual In-line Memory Module) Memory that is half the size of DIMMs, are available in 32- or 64-bit data pahts, and are commonly found in laptops and iMac systems.
TCP
(Transmission Control Protocol) A protocol in the TCP/IP suite operating at the transport layer to provide connection-oriented, guaranteed delivery of packets. Hosts establish a session to exchange data and confirm delivery of packets using acknowledgements. This overhead means the system is relatively slow.
touchpad
Input device used on most laptops to replace the mouse. The touchpad allows the user to control the cursor by moving a finger over the pad's surface. There are usually buttons too but the pad may also recognize "tap" events and have scroll areas.
virtual switch
A software application that enables communication between VMs.
AES
Advanced Encryption Standard) Modern encryption suite prove providing symmetric encryption (the same key is used to encrypt and decrypt). AES is a very strong cipher with many applications, including being part of the WPA2 Wi-Fi encryption scheme.
AFP
(Apple Filing Protocol) Protocol supporting file sharing on MacOS networks. AFP works over TCP port 548
agent
A process running on an SNMP compatible network device that sends information to an SNMP manager.
AHCI
(Advanced Host Controller Interface) A logical interface used by SATA drives to communicate with the bus
airplane mode
A toggle found on mobile devices enabling the user to disable and enable wireless functionality quickly.
all-in-one unit
A desktop computer in which all the computer components, except the keyboard and mouse, are contained within the monitor case.
ALU
(Arithmetic Logic Unit) A circuit in the CPU that perfomrs integer-based calculations and performs bit-wise logical calculations.
AMD-V
Extension in AMD-based systems that allow hardware virtualization.
AMD64
AMD's 64-bit instruction set that was also adopted by Intel for its 64-bit desktop and mobile line. Intel refer to it as EM64T or Intel 64
analog display
A computer monitor that accepts continuously varying signals. CRT monitors use analog signals and are capable of supporting several output resolutions without losing quality.
Android Auto
An Android phone feature that allows users to interact with their phone using voice commands and a vehicle;s built-in display.
anti-glare cover
A display cover to deal with ambient lighting issues on the display.
antistatic bag
A packaging material containing anti-ESD shielding or dissipative materials to protect components from ESD damage
AP
(Access Point) A device that provides connectivity between wireless devices and a cabled network. APs with Internet connectivity located in public buildings (cafes, libraries, and airports, for instance) are often referred to as hotspots.
APIPA
(Automatic Private IP Addressing) A means for Windows clients configured to obtain an address automatically that could not contact a DHCP server to communicate on the local subnet. The host randomly selects an address from the range 169.254.x.y. This is also called a link-local address.
App Store
The online site where Apple users can purchase or get free apps that have been submitted to and approved by Apple before they are released to users.
Apple CarPlay
An iPhone feature that allows users to interact with their phone using voice commands and a vehicle's built-in display.
Application protocols layer
In the TCP/IP suite, numerous protocols used for network configuration management, and services reside at this level. Application protocols use a TCP or UDP port to connect the client and server.
application virtualization
Rather than run the whole client desktop as a virtual platform, the client either accesses a particular application hosted on a server or streams the application from the server to the client for local processing.
apps
Installable programs that extend the functionality of the mobile device that must be written and compiled for a particular mobile operating system (Apple iOS, Android, or Windows).
AR
(Augmented Reality) Using software and smartphone cameras or headsets to interact with real-world objects and images or change the way they appear in some way.
ARP
(Address Resolution Protocol) When two systems communicate using IP, an IP address is used to identify the destination machine. The IP address must be mapped to a device (the network adapter's MAC address). ARP performs the task of resolving an IP address to a hardware address. Each host caches known mappings in an ARP table for a few minutes. It is also a utility used to manage the ARP cache.
ASF
(Auto Sheet Feeder) IN an inkjet printer, the paper pickup mechanism to feed paper into the printer.
aspect ratio
A characteristic of display devices that indicates the ratio of width to height
AX
A standard PC case, motherboard, and power supply specification. Mini-, Micro-, and Flex-ATX specify smaller board designs.
audio subsystem
Made up of a sound card and one or more audio input and output devices.
authentication
A means for a user to prove their identity to a computer system. Authentication is implemented as either something you know (a username and password), something you have (a smart card or key fob), or something you are (biometric information). Often, more than one method is employed (2-factor authentication).
back haul
A link or transit arrangement with another ISP to connect each Point of Presence to their core network infrastructure and one or more IXPs.
backed up print queue
A problem situation where there are lots of jobs pending but not printing.
backlight
Fluorescent lamp illuminating the image on a flat panel (LCD) screen. If the backlight or inverter fails, the screen image will go very, very dark.
barcode scanner
A barcode reader is a handheld or penshaped device designed to scan barcodes. A barcode is a pattern of different sized parallel bars, typically representing a product number, such as an ISBN, EAN, or UPC. The reader uses a sensor mechanism (typically either a photo diode, laser, or CCD) to read the intensity of light reflected back by the barcode. The reader then reports the number back to application software, which links it to a product database.
baseband update
Modification of the firmware of a cellular modem.
BD
(Blue-ray Disc) The latest generation of optical disc technology that uses a 405 mm blue laser for high density storage, with disc capacity of 25 GB per layer. Transfer rates are measured in multiples of 36 MBps
biometric devices
Peripherals used to gather biometric data for comparison to data stored database.
biometrics
Identifying features stored as digital data can be used to authenticate a user. Typical features used include facial pattern, iris, retina, or fingerprint pattern, and signature recognition. This requires the relevant scanning device, such as a fingerprint reader, and a database of biometric information (template).
BIOS
(Basic Input/Output System) Firmware that contains programs and information relating to the basic operation of PC components such as drives, keyboard, video display, and ports. It also contains specific routines to allow set-up configuration to be viewed and edited and it contains the self-diagnostic Power-On Self Test (POST) program used to detect fundamental faults in PC components. BIOS can also be used to secure components not protected by the OS by specifying a supervisor password (to prevent tampering with BIOS settings) and a user password (to boot the PC).
BIOS setup
(Basic Input/Output System setup) Another name for the setup program used to configure system firmware settings. Also known as CMOS setup or UEFI setup.
bitmap image data
A pixel-by-pixel image sent to a printer to print a file.
blacklisting
An address added to the black list is prohibited from connecting to any port.
blanking plate
Metal strips that cover unused adapter slots in the case so the proper air flow is maintained within the system case.
BLE
(Bluetooth Low Energy) A radio-based technology designed for a small battery powered devices that transmit small amounts of data infrequently. BLE is not backwards-compatible with "classic" Bluetooth, though a device can support both standards simultaneously.
Blue-ray drive
An optical drive for reading, and if so equipped, writing to Blue-ray disc media. Most drives can also read CD and DVD discs.
Bluetooth
Short-range radio-based technology working at up to 10 m (30 feet) at up to 1 Mbps used to connect peripherals (such as mice, keyboards, and printers) and for communication between two devices (such as a laptop and smartphone).
bookmark
A record of a website or web page that you visited.
boot sequence
The order in which the system firmware searches devices for a boot manager.
BRI
(Basic Rate Interface) a class of ISDN service that provides two 64 Kbps (B channels) for data and one 16 Kbps (D channel) for link management control signals
bridge
A bridge can be used to divide an overloaded network into separate segments. Intrasegment traffic (traffic between devices on the same segment) remains within this segment and cannot affect the other segments. A bridge works most efficiently if the amount of intersegment traffic (traffic between devices on different segments) is kept low. Segments on either side of a bridge are in separate collision domains but the same broadcast domain. The function of bridges is now typically performed by switches.
broadband
The technical meaning of broadband is a transmission that divides the available media bandwidth into a number of transmission paths or channels. WAN signaling generally uses this form of transmission and consequently the term is used generally to refer to 2 MBps+ Internet links such as as DSL or cable.
broadcast address
A packet sent to all hosts on the local network (or subnet). Routers do not ordinarily forward broadcast traffic. The broadcast address of IP is one where the host bits are all set to 1; at the MAC layer, it is the address ff:ff:ff:ff:ff:ff.
BSSID
(Basic Service Set Identifier) The MAC address of the access point.
Bubblejet
The term used by the Canon company to refer to their thermal inkjet print method.
burning
In optical discs, the process of using a special laser used to transform the dye to mimic the pits and lands of a premastered CD.
bus
Buses are the connections between components on the motherboard and peripheral devices attached to the computer. Buses are available in industry standard formats, each with its own advantages and disadvantages. The standard functions of a bus are to provide data sharing, memory addressing, power supply, and timing. Common bus types include PCI, PCI Express, and USB.
bus mastering
Feature of a bus allowing devices to communicate with one another without going through the CPU. Bus mastering is supported by most bus types, including PCI, SCSI, and ATA (in "Ultra DMA" modes).
cache
A small block of high-speed memory that enhances performance by pre-loading (caching) code and data from relatively slow system memory and passing it to the CPU on demand.
CAD
(Computer-Aided Design) Software that makes technical drawings and schematics easier to produce and revise.
calibration (printer)
The process by which the printer determines the appropriate print density or color balance, or how much toner to use.
CAM
(Computer Aided Manufacturing) Software that can control machine tools found in manufacturing environments.
CAN
(Campus Area Network) A network that spans multiple nearby buildings.