# Computers glossary - part 3

## I

I/O - input/output, a common identifier for most computers since some peripherals serve both purposes

IC - integrated circuit, a computer chip built into a circuit board

ICR - intelligent character recognition, aka intelligent OCR, a more advanced form of OCR that uses a trained machine learning model to identify text

IDE - integrated development environment, an all-in-one solution for programmers to write, debug, test, and compile programs

IDF - intermediate distribution frame, a large-scale network hub, often located in another room, designed to assist the MDF

Idempotent - a resource that, if used multiple times, will create the same consequence as if it were used once (e.g., submitting data 3 times creates the same result as submitting it once)

Identity - in computer science, where the data type isn't swapped out before testing whether two data elements are the same, represented by ≡

Idiom - an algorithmic structure that syntax builds into

IDS - intrusion protection system, software that detects that intruders are/were hacking a computer, contrast to IPS

If loop - a function that only activates if conditions are met (e.g., if x=1, do something)

Implementation - the way a thing gets applied, instead of an abstraction

In-band - inside a natural hardware environment, often remotely, contrast to out-of-band

Incrementer - a logic gate that adds 1 every time it's activated

Indie game - independent game, a game with a modest or nonexistent production and marketing budget

Information architecture - a structure that informs people where they are in an interface relative to everywhere else

Initialize - to begin with a value, such as a variable

Input - anything that goes into a computer, from typing to information from other computers

Input mask - database entry constraints for the user typically as either text-only, numbers-only, or a set limit of characters

Insertion sort - a sorting algorithm that repeatedly compares each database entry with the previous ones and places them where they fit in the middle of the already-sorted data, takes half the time as bubble sort

Integer - a whole number with no decimals

Integration - things that are intimately connected with each other

Interface - the designed thing that lets a person/computer interact with a computer, called an API if it's for a computer

Internet - the world's largest computer network, connecting most of the computers across the world into one complicated super-network

Interoperability - different things work together

Interpolation - a mathematically established approximation given other multiple known points

Interpreter - computer code that converts high-level programming language into assembly or machine code line by line (typically during runtime), contrast to compiler

IoT - Internet of things, every device, even special-use ones, has an IP address, creating tremendous opportunities as well as [cybersecurity](computers-cysec.md) risks

IP - internet protocol, the standard for networking across the internet, can also refer to [intellectual property](legal-ip.md)

IP address - a numerical label a computer needs to communicate on the internet, can be IPv4 or IPv6 or both, can be a public IP address (for the internet) or private IP address (for a local network)

IPAM - IP address management, software that tracks and gives updates on IP addresses (usually local network IPs)

IPC - inter-process communication, information stored to communicate between various operating system tasks

IPMI - intelligent platform management interface, a software designed to track many components across a distributed system, often out-of-band

IPS - intrusion protection system, software that stops intruders from hacking a computer, in contrast with IDS

ISA - instruction set architecture, an abstraction that involves taking instructions and following them carefully, most popular implementation in the CPU

ISP - internet service provider, an [organization](groups-large.md) that provides internet service

Iteration - a repeatable, simple task

IWR - intelligent word recognition, an advanced form of ICR that can parse entire words instead of simply characters

## J

JavaScript - a scripting language that drives the internet alongside HTML and CSS

Journaling - file system programming that keeps a record file in long-term memory of tasks the CPU still has to do, very useful if the task is interrupted and can't continue

Jumbo frames - frames that exceed the MTU, usually involved with getting faster speeds from virtualization

Justified - aligning text by adjusting the kerning to where *both* the left and right sides are aligned

## K

Kerning - the space between letters

Key - can refer to an associative array's reference, a physical button that corresponds to a character, or a code that encrypts/decrypts data

Key/value pair - matching values to a unique number, used in an associative array and in most databases

Keyboard - the primary input for most general-purpose computers, typically has a QWERTY layout based on typewriters from the past, sends electrical pulses to memory

Keyboard debouncing - using a fix to prevent key bounce

Keyboard matrix - a circuit board diagram that maps keyboard keys to corresponding signals

Key frame - a method of feeding graphical information on a percentage scale for several states, then the computer seamlessly transitions from one to the next, an easy method for animation in web design

Keylogger - software that tracks keystrokes, can be user-installed or malware

Keyword - specific words that create language associations for users

Key bounce - a situation when a key is registered multiple times with one key press

Kill chain - a hacker's necessary sequence to successfully send a payload through an exploit

Killer app/feature - software or a feature that is so remarkable that it justifies buying the computer just for that thing alone (e.g., Microsoft Office at one time)

Knowledge worker - a person who works with software, typically refers to developers

Known good - a diagnostic term referring to something that is proven to have worked recently, since many new parts can be defective and configurations can frequently change

KPI - key performance indicator, a measurement that management often uses to define success

## L

L2TP - Layer 2 tunneling protocol, a core component of how VPNs work

LAN - local area network, smaller computer networks, in contrast with WAN, Ethernet is the only surviving protocol for it

Lang - short for "programming language", a defined set of possible instructions a user can pre-define for a computer

Latency - delay, usually referring to network speed or memory transfer

LCD - liquid crystal display, a type of screen where each pixel's light intensity of all 3 colors is dictated by rotating crystals and backlit by a fluorescent lamp

Leaderboard - an internet high score system for games

LED - light-emitting diode, a small light, often used for LED screens that are like LCD screens but with LEDs instead of fluorescent tubes

Leech - to receive information over a P2P connection, often refers to leeching a torrent

LEGO - a fun toy that's been around a while, great to start small children on STEM

LGA - land grid array, where the pins for the chip are on the circuit board, meaning the board would need replacing if the pins are bent

Library - a collection of computer code that vastly expands the functionality of a high-level language, can be downloaded in entirety or specific classes of it

Lidar - light detection and ranging, determining a location and distance using emitted light

Line - a line of text up until it hits a return, often refers to a single instruction of code

Link-state routing protocol - a protocol that counts the number of bounces between points and picks the route with the fewest bounces, in contrast with distance-vector routing protocol

Linked list - a list with references at the end of each list item, an alternative to storing the list in memory

Linux - an open-source Unix-like operating system kernel, can also refer to the variety of Linux distros

Liquid layout - a ratio determined by a percentage inside an element or screen instead of by pixel size

List - Multiple data put together, doesn't have to be the same type

LLC - logical link control, a subset of the [Data Link layer](networks-computer.md) that deals with directing information to and from various nodes, moves from media access control (MAC)

Load - a logic gate selector to dictate whether a register should hold the old information or overwrite it with the new information

Load balancer - an enterprise-grade software that manages processing needs across multiple computes

Local - broad concept for something that's nearby, contrast to remote

Lock - a GPS device successfully detecting the distance from a GPS satellite

Location-based AR - aka position-based AR or geo-based AR, an AR system that requires specific location data to present information

Lock file - a file that tracks that another file is getting used

Lockstep networking - a P2P networking arrangement where two or more computers are matching the same state, necessary for online video games

Logarithm - a mathematical formula where each additional increment is only marginally more than the previous, the opposite of exponents (e.g., log^~2~^(8)=3 while 2^3^=8)

Log file - a plaintext output of runtime events, including runtime errors

Logic error - a situation where a program runs perfectly fine, but outputs the wrong thing compared to what the programmer actually wanted (e.g., outputting 4 instead of 5)

Logic gate - a small logic module, usually transistor-based, that specifies a flow of logic, typically driven by a NAND or NOR gate primitive

Logical memory - the amount of memory a computer interprets it has, contrast to physical memory

Loop - a cycle that repeats itself a lot in a computer

Loot box - a game development strategy to create randomized incentives, tends to extend playtime

Low-pass filter - a signal filter that only permits lower audio/video frequencies through, prevents aliasing

LSA - link state advertisement, protocol that informs other computers of its linked computers

Ludonarrative - the difference in a game between how the game world and the story work

## M

MAC - media access control, a subset of the [Data Link layer](https://gainedin.site/networks/) that deals with labeling various nodes, moves to logical link control (LLC)

MAC address - media access control address, a unique identifier for network-enabled computer parts, uses hexadecimal and often uses colons for ease of reading (e.g., 0f:4c:3b:a5:a3:d1)

Machine code - binary information that computers work with, often directly translates from assembly code from a high-level language

Machine learning - an algorithm designed to track a flow of repetitive trained information, then repeat back permutations of that information

Magic pixels - the edge pixels of a screen, named because of their relatively easy UX compared to the rest of the screen

Magnet link - a hash for a BitTorrent client to open and interpret, contains information about that torrent and its contents

Mainframe - an enterprise-grade computer that often has many terminals/endpoints

Malvertising - ads that direct to malicious software that are designed to look like legitimate software

Malware - malicious software, designed by a hacker to destroy or steal

Man-in-the-Middle (MitM) attack - a hack that involves appearing legitimate while standing in the middle of a transaction, the mobile version is Man-in-the-Mobile

Managed services - a technology contract with a routine fee to keep technology running, contrast with break-fix

Map - to make a link between something and something else, such as mapping a game controller button to a keyboard key

Markdown - a lightweight markup language, useful for maintaining formatting elements (e.g., headings, hyperlinks) when storing things as plaintext

Marker-based AR - augmented reality that displays content on top of an image

Markerless AR - augmented reality that simply needs an empty space

Master - aka main (now that [Leftism](politics-leftism.md) has gotten offended at it), a dominant drive or record that has a higher importance than others, contrast to slave

Matrix - a grid of data

MBR - master boot record, a relatively small record placed at the beginning of a hard drive that indicates what's on that drive and what memory register to start accessing it

MDF - main distribution frame, the location for most of a data center's network activity, may connect to an IDF

Media - information expressed via a medium, typically refers to audio, video, and image files

Media query - a set of CSS styles that activate when a property of a media is activated (e.g., min/max width/height on a screen/printer)

Megatransfer - 10^6, or 1,000,000, cycles per second, measured specifically for data transfer, also known as MB/s

Memory - stored information, can be short-term (like RAM) and deleted on power-off, or long-term (like HDD) and stored between power cycles

Memory hierarchy - the engineering reality that you can't have lots of memory that's also fast, so there's a constant speed/amount tradeoff that visually looks like a pyramid (e.g., 5 kb @ 10,000 writes/sec vs. 5,000 kb @ 1,000 writes/sec)

Memory leak - memory in that was heap allocated, but the program wasn't instructed to release it when it was finished, creates stack overflows and other weird issues

Memristor - memory resistor, a relatively new component made of electric switches that hold their memory even without electrical charge

Merkle tree - aka hash tree, a data structure that converts each element into a hash, then makes hashes off multiple hashes, until there's eventually 1 hash for all of it.

Merge - a necessary and complicated procedure of combining code bases together, a core feature of Git

Metadata - quick-access information placed in the header of a file meant to make managing the files easier without the computer having to dig through them each time

Metrics - measurements

Microcomputer - aka mini, an old term for a silicon-based computer, rather than older vacuum tube computers

Microcontroller - affordable, cheap computers with a very limited capacity and are designed to do a relatively small set of computing tasks, often to serve a more robust computer elsewhere

Microkernel - an operating system kernel architecture that has a minimalist system management that takes up less memory, contrast with monolithic kernel

Middleware - software designed to be in the middle of other things

MIDI - musical instrument digital interface, a standard that sends musical instrument input to time-mapped data

MIDI voice - sounds mapped to MIDI inputs, which permits a musical instrument to play as an entirely different instrument at the user's preference

Mining - creating a new block in a blockchain, often is *very* resource-intensive, especially with cryptocurrency

MMU - memory management unit, a specialized component that connects virtual and physical memory locations, uses the translation lookaside buffer

MNO - mobile network operator, the organization that manages a cell tower, compare to MVNO

Modal window - a pop-out context window in design that temporarily locks out interaction with other elements

Mode - a state that allows for more varieties or iterations of inputs or outputs

Modem - modulator/demodulator, translates information for sending via a network, then translates back for the computer to use, usually built right into the motherboard

Modular - components of something are interchangeable

Module - aka subsystem, an independent piece of a larger thing

Modulo operator - A math calculation represented by % that effectively returns the remainder of a division operation, not to be confused with a modulus (the entire *range* of numbers that fit in that operation's set)

Monolithic kernel - an operating system kernel architecture that encompasses almost all aspects of system management at the expense of taking more memory and everything running as superuser, contrast with microkernel

Monospaced font - a font that uses the same width for each character, popular in older computers and with ASCII art

Motherboard - a specific printed circuit board designed to have at least a CPU, input, memory, and output

Motion blur - a camera artifact caused by the aperture being open too long or an object moving too fast, a convenient way to cut down on graphics load

Mount - to connect a partition to a computer for accessing, can be a hard drive or external media

Mount file - a file used as a placeholder for a temporary file system, such as a virtual machine

Mouse/Trackball/Touchpad - a peripheral that sends x/y coordinates into the computer using relative motion, represented by a cursor on the screen

Move - either copying computer code and deleting the original, or re-linking an association in memory (such as in a hierarchical file system)

MTU - maximum transmission unit, the limit of how large a frame can get, can be subverted by jumbo frames

MU-MIMO - multiple-user multiple-input multiple-output, a transceiver configuration that allows the most bandwidth on a network compared to SU-MIMO or SISO

MVNO - mobile variable network operator, organizations that rent out the extra bandwidth from MNOs' cell towers

Multi-licensing - issuing multiple types of software license for the same software product

Multimap - a data structure where the key is designed to grab more than one value

Multiplexer - a logic gate where one set of inputs is a selector to determine which of the inputs will go out

Multiset - a data structure that's a set, but can store multiple values of the same thing

## N

N-key rollover - the maximum number of keys that can be reliably pressed on a mechanical keyboard before noticing ghosting/blocking, requires diodes so higher n-key rollover will cost more

Name server - a computer in a DNS that stores a record of domains corresponding with IP addresses

Namespace - a system that separates things into groups to allow the same names across multiple areas, very useful for programming

Nanosheet - a panel of *tiny* transistors, also known as nanoribbon, nanowire or gate-all-around device, depending on who you ask

NAS - network-attached storage, a computer designed to do nothing but keep information available on a network

NAT - network address translation, converting IPs into other IPs, necessary for IPv4 when they started running out of IPs but not necessary for IPv6

Netcode - computer code that executes across a network, often refers to internet-based games

Nested function - a function inside a function, extremely useful but can get complicated to follow the code (especially if there's a recursion)

Network - computers connected where they can send and receive data

Network edge - the closest network connection to the endpoint

Network interface card - aka NIC, a device that's designed to connect to a network, can be a peripheral or built straight into a motherboard

Network sniffing - using software to capture packets, can be used for hacking or for diagnostics/learning

Neural network - a mechanism of machine learning that consists of a network of individual rule-defining components

NFT - non-fungible token, a unique cryptographic token for something, refers to blockchain

Node - very broad word for a place on a network that has connections to other things

Noise floor - the minimum amount of white noise that exists throughout a recording

Non-diegetic - not naturally part of the established environment, such as lighting or sound

Nonce - unimportant code that's used to validate a cryptographic hash

Non-validated input - an exploit that involves entering data information in a way that the computer mistakes it for code

Non-volatile/Long-term storage - memory that persists in between power cycles (i.e., non-volatile), often is a hard drive or removable media, opposite of volatile storage

NOP - an opcode for no operation, which basically tells the computer to wait for a cycle

NOP slide - an exploit that slides data into NOP opcodes

Normalize - make a database have less memory, but with a longer read time, opposite of denormalize, an alternately mean reducing data into a canonical form

NoSQL - any database that isn't strictly a relational database

Null - a completely blank value in memory, it's *not* a "zero" value

## O

OCR - optical character recognition, software that detects [language](language.md) on scanned media

OEM - original equipment manufacturer, the organization that creates the original components of a computer, can often be several organizations removed from the group that actually sells the whole computer

OLED - organic light-emitting diode, the next technological evolution of the plasma screen, not at all associated to LED screens despite the name

OMR - optical mark recognition, informally called scantron, a method of computer input that involves reading marks on a paper

Onboarding - the UX from first initializing software that stores configuration information and starts differently the second time onward

On-prem - on-premises, having a computer that you can physically touch

One-to-one correspondence - one instruction creates one machine code instruction, the major limitation of low-level languages

Opacity - how opaque, or invisible, an element or color is

Opcodes - operation codes, control bits of an ALU that determine which logic to run on the inputs

Open-core - software that is open source, but has a proprietary implementation or front-end that isn't

Open-source - computer code that's free to view and therefore modify, allows for easier debugging at the risk of losing potential profit off it, often contrasts to proprietary software or closed-source

Operating system - the large system that runs the basic things in a computer, is most often Windows, Mac, or Linux in most general-purpose computers

Oscillator - something that goes back-and-forth to track time, a major component of a clock

OSINT - open-source intelligence, any potentially useful information or information-gathering tool

OSPF - open shortest path first, a link-state routing protocol

Out-of-band - outside a natural hardware environment, often remotely, contrast to in-band

Output - any information the computer sends out, which could be anything from a screen to other computers

Overclocking - cranking up the speed of the computer beyond the manufacturer specifications, which may make better benchmarks but might melt your processor, opposite of underclocking

Overflow - the leftmost carry gets dropped in adding, a huge difference between computer math and algebra (e.g., 1000 plus 1001 makes 0001 instead of 10001)

Overhead - a general concept usually referring to maintenance cost, space, electrical use, or processing power

Over-provisioning - giving more resources than necessary, can be a good idea or a bad idea depending on whether you want redundancy or efficiency, opposite of under-provisioning