Computer/System Terms - A
absolute time in pre-groove (ATIP) - (writable compact discs)
Accelerated Graphics Port (AGP) - (An Intel-designed video bus (component carrying information between the motherboard and system components) introduced in 1997 for high-performance graphics and video systems. Replaced by the faster PCI (peripheral component interconnect) Express (PCIe).)
accelerated hub architecture (AHA) - (Network architecture setup involving a device, similar to a switch or router, which receives incoming data packets.)
accelerated processing unit (APU) - (also known as a graphics processing unit (GPU)) (Component of a PC video system (video display adapter) which processes graphics data and transmits the signals which will appear on the computer monitor. APU is the term used by AMD for its processors.)
Access Control (AC) - (A method or process that defines the degree of access granted to use a particular resource, data, systems, or facilities. The resource may be physical, such as computers, switches, or routers, or job-related, such as permissions to use or view a file, or folder.)
access control list (ACL) - (A clearly defined list of permissions that specifies what actions an authenticated user may perform on a shared resource. Access control lists are used in many different contexts in security. They may be used within a system to allow or deny access to certain files or folders, even if the user has been authenticated, or on a network device, such as a router, to allow or deny access to a system.)
access point (AP) - (wireless access point) (A network device that provides a connection point for hosts to enter a network, although most often associated with wireless clients. For wireless systems, usually a low-power transceiver (transmitter/receiver) that is connected to the local area network (LAN) through a standard network connection.)
acknowledgment (ACK) - (A Transmission Control Protocol (TCP) communication message used for system communication sessions. When a host receives a SYN (synchronous) from another host signaling that the other host wants to initiate a communication session, the receiver acknowledges the request by sending a SYN/ACK packet. The initial host responds with an acknowledgment (ACK) packet indicating that it received the SYN/ACK packet and is ready to begin the communication session.)
Action Message Format (AMF) - (A communication format used for messaging between Adobe Flash clients and a remote service.)
Active Server Pages (ASP) -
Adaptive Contrast Management (ACM) - (Name given by the Acer computer manufacturer for its dynamic contrast ratio computer screen. Dynamic contrast ratio is a method of measuring the brightness of liquid crystal display (LCD) computer monitors.)
Adaptive Differential Pulse Code Modulation (ADPCM) - (Algorithm used by manufacturers of audio adapters to reduce/compress the file size of sound recordings to a smaller size for storage so that the file takes up less room when stored.)
Address Resolution Protocol (ARP) - (Protocol which correlates the IP (Internet Protocol) address number assigned with the phsical hardware/computer address based on the network interface card (NIC). Correlates the media access control (MAC) address (48-bit address burned into each network card), with a known IP address.)
address space identification (ASID) -
address space layout randomization (ASLR) - (memory addressing)
Address Supporting Organization (ASO) -
Advance Technology eXtended (ATX) -
Advanced Access Content System (AACS) - (Anti-copying protection system intended to prevent copying of commercial media content, such as music or movies. AACS is used on Blu-ray video discs.)
Advanced Clock Calibration (ACC) - (Method or feature for adjusting the speed, timing and voltage settings of a computer's central processing unit (CPU) memory components.)
Advanced Configuration and Power Interface (ACPI) - (A standard method for integrating power management, as well as system-configuration features throughout a PC, including the hardware, operating system (OS), and application software. Initially released in 1996, one of the main function changes introduced was to move power-management functions from the basic input/output system (BIOS) to the operating system (OS).)
Advanced Host Controller Interface (AHCI) - (Industry-standard, high-performance interface to system driver/operating system (OS) used for discovering and implementing advanced features, such as hot plugging and power management. Simplifies the installation of operating systems.)
advanced Linux sound architecture (ALSA) - (Standard for sound card adapters for audio sound recordings using Linux drivers.)
Advanced Mobile Phone System (AMPS) - (First usable cellular data network, developed by Bell Systems, introduced in 1978. Also referred to as 1 G (first-generation). AMPS was an analog network which provided only basic network services, was not encrypted, and was not considered secure.)
Advanced Optical Disc (also known as HD-DVD (High-Definition Digital Versatile Disc) (AOD) - (Now-defunct optical disc format which lost to Blu-ray disc (BD) format in the video market.))
advanced persistent threat (APT) - (Term used for long-term threats, or attacks which are not limited to one-time attempts to access a system. Usually applied to very skillful, well-funded, and sometimes nation-state supported attackers.)
Advanced Power Management (APM) - (Standard method for integrating power management, as well as system configuration features throughout a PC. Replaced by Advanced Configuration and Power Interface (APCI).)
Advanced Programmable Interrupt Controller (APIC) - (Processor in a motherboard's chipset which controls hardware interrupts, or signals to the motherboard that a new request or program routine has priority and must be fulfilled.)
advanced run length limited encoding (ARLL) - (Method of disk encoding (converting raw binary data into a form which can be stored on disk) which allows for higher density storage. RLL proved unreliable and is considered obsolete.)
advanced technology (AT) -
Advanced Technology Attachment (ATA) -
Advanced Technology Attachment Packet Interface (ATAPI) -
advanced vector extensions (AVX) - (processors)
Advanced Video Coding High Definition (AVCHD) -
ahead of time compilation (AOT) - (Type of interpreter compiling which translates original code into bytecode, a type of intermediate code which can be converted to machine code, before sending it to the microprocessor for execution.)
All-in-One system (AiO) - (Term for completed or assembled PC, consisting of individual systems, in the context of a purchase of a completed PC and system components, in contrast to assembling or building a PC from scratch using the individual system components.)
Alternate Data Stream (ADS) - (Term used by the Microsoft Windows system for files created or originating from a source outside the Windows system. Attempting to download files, such as .zip files, from the Internet, will cause a warning display that the file is from an untrusted source, and the file will be tagged with an alternate data stream (ADS) extension for all future donwload attempts.)
alternating current (AC) - (Electric current with regularly changing polarity - current which flows first in one direction and then the other.)
Amazon Web Services (AWS) -
American Megatrends, Inc. (AMI) - (Company specializing in the development of ROM BIOS (read-only memory basic input/output system) software used in motherboards, which is licensed to the manufacturer.)
American National Standards Institute (ANSI) - (Organization composed of government agencies, organizations, educational institutions, businesses, and individuals which sets standards and provides guidelines in various sectors of business, including software development and computer system operations.)
American Power Conversion (APC) - (Company providing power protection equipment, such as uninteruptible power supply (UPS) and standby power supply (SPS) systems.)
American Registry for Internet Numbers (ARIN) - (A regional Internet registry (RIR) - a not-for-profit organization that maintains data on companies, organizations, or individuals - for those who have registered their IP addresses in America, Canada, some Caribbean countries, and North Atlantic islands.)
American Standard Code for Information Interchange (ASCII) - (A standard code for representing characters as numbers that is used on most microcomputers, computer terminals, and printers.)
analog-to-digital converter (ADC) - (A small computer chip built into an adapter which converts analog sound waves into digital bits that a computer can understand.)
Analog Protection System (APS) - (Protection system employed to prevent or limit copying of recorded material or commercial media, such as movies, on DVD-Video discs.)
annualized (annual) rate of occurrence (ARO) - (The number of times a negative event is expected to occur on a yearly basis.)
anisotropic magneto-resistant head (or magneto-resistive head) (AMR) - (Type of read/write head used to read data stored on PC hard disk drives and to write/save data to hard disk drives.)
antiferromagnetically coupled media (AFC) - (Method of coating hard disk platters for magnetic information storage which involves two magnetic layers separated by a thin, 3-atom film layer or the element ruthenium.)
Application Information (Appinfo) - (Service in the Windows operating system which mediates session access.)
application program (app/apps) - (A piece of software that performs a particular function or service for the user. Can be complex, such as a spreadsheet, or a limited-purpose program which simplifies or automates processes, such as smartphone downloadable app which provides quick access to a website or a banking app which allows for account access or facilitates deposits.)
application programming interface (API) - (A software application which allows two different applications or devices to communicate, such as a computer and a printer, by converting an application communication into a format which the sending or receiving device can understand, e.g., encrypting a plaintext message.)
application service/server provider (ASP) -
architecture description (AD) - (A formal description and representation of a system, the components that make it up, the interactions and interdependencies between those components, and the relationship to the environment.)
arithmetic logic unit (ALU) - (Component of the Central Processing Unit (CPU) which performs mathematical functions and operations on data.)
artificial intelligence (AI) - (Computing devices capable of "learning," assessing new information, and changing actions to accommodate. In its purest form, it means the ability to simulate human thinking, to be able to "think" like a human. In practical terms it has come to mean the ability to collect and analyze large amounts of data, to respond to situations encountered, to improve responses (or to learn from incorrect responses), and to increase the speed of analysis and response. Machine learning (MI) is the capability of computers to improve their responses based on new information. The concept of AI has also been applied, in its ordinary sense, to specific areas where computers can perform specific tasks with greater speed, such as in calculations, or in the ability to mimic or duplicate human capabilities, such as voice recognition, or pattern recognition.)
artificial neural network (ANN) - (A mathematical or computational model based on the neural structure of the brain.)
Asia-Pacific Network Information Centre (APNIC) - (Regional Internet registry (RIR), a not-for-profit organization that maintains data on companies, organizations, or individuals in the Asia-Pacific region that have registered their IP addresses.)
assembler language - (A program for translating assembly-language programs into binary machine instructions - An intermediate language between high-level languages, understood by humans, and machine-level instructions, understood by the machine.)
Association for Computing Machinery (ACM) - (Nonprofit organization of educators, researchers, and professionals involved in the computer science field, founded i 1947.)
ASUS (company) Smart Contrast Ratio (ASCR) -
Asymmetric Digital Subscriber Line (ADSL) - (Digital subscriber line - type of high-speed connection technology used to connect a home or business to the service provider's central office - where data travels downstream faster than upstream. General used by residential customers.)
Asynchronous Transfer Mode (ATM) -
Atanasoff-Berry Computer (ABC) - (Considered the first true digital electronic computer, developed from 1937 to 1942 by John V. Atanasoff and Clifford Berry.)
Atomicity, Consistency, Isolation, and Durability (ACID test) - (or Atomic, Consistent, Isolated, and Durable) (In the area of database management dealing with online transaction processing (OLTP), the ACID test is a summary of the safeguards, or system characteristics intended to maintain database integrity and prevent the entry of erroneous, incomplete, or corrupted data. Atomicity divides transactions into units and prevents entry unless all changes take effect. Consistency requires that data in one database be consistent with other data in that database. Isolation requires that transactions execute in isolation until completed. Durability prevents rolling back transactions once they have been committed.)
attachment unit interface (AUI) -
attack surface (AS) - (The components of a system that a hacker/attacker can hack or gain access to - e.g., installed software and services, endpoints, e-mail and Internet connections, printers and attached devices, or Internet of Things (IoT) devices.)
Attestation Identity Key (AIK) - (Key used for the attestation of the Trusted Platform Module (TPM) chip itself to service providers. The TPM microchip is installed on the motherboard of computers and is dedicated to carrying out security functions that involve the storage and processing of symmetric and asymmetric keys, hashes, and digital certificates.)
Audio Modem Riser (AMR) - (Communications and networking riser (CNR)) (A special dedicated connector for riser cards designed for specific motherboards offering communications and networking options. A riser is a small circuit board inserted perpendicularly into a motherboard, containing slots for cards.)
audio stream input/output (ASIO) -
authentication, authorization, and accounting (AAA) - (a system process/security function requiring the system to authenticate computers/users attempting to access the system, usually by some form of credential, to authorize the user by granting permission for some level of use, and accounting for, or tracking the amount of use, such as connection time and billing.)
authentication server (AS) - (A server in a key encryption system, which authenticates a user by means of a pre-exchanged secret key based on the user's password.)
Automated Teller Machine (ATM) - (Banking)
Automatic Data Processing, Inc. (ADP) - (Company providing human management software, including payroll and HR solutions, tax compliance and benefits administration, founded in 1949.)
automatic gain control (AGC) - (Type of circuitry in the disk drive audio adapter which adjusts recording levels for DVDs (digital versatile disc).)
Autonomous System (AS) - (Term for individual networks on the Internet, which are independently controlled by different service providers and organizations.)
Autonomous System Number (ASN) - (organization identification number)