ToolDirectory.AI · Reference

AI Glossary

A plain-English reference for the 120 terms that show up most in our AI tool reviews — from agents and embeddings to retrieval-augmented generation. Each entry is written by our editors and updated monthly.

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120 of 120 terms

A20 entries

Agent

Agents & tools

An AI system that can take actions, use tools, and make decisions autonomously to complete a goal. Read about Agent →

AGI

Core concepts

Artificial General Intelligence — a hypothetical AI that matches or exceeds human ability across virtually any intellectual task. Read about AGI →

AI

Core concepts

Artificial Intelligence — software that performs tasks normally requiring human intelligence, like understanding language, recognising images, or generating content. Read about AI →

AI Assistant

Core concepts

A conversational AI tool that helps users with tasks like writing, scheduling, research, or answering questions in natural language. Read about AI Assistant →

Alignment

Safety

The challenge of making AI systems behave in ways that match human values and intentions — not just their literal instructions. Read about Alignment →

API

Infra & cost

An interface that lets developers send requests to an AI model and get responses programmatically — the way most AI tools talk to LLMs. Read about API →

Adversarial Attack

Safety

Deliberately crafted inputs that trick an AI model into producing wrong or harmful outputs — a key category of AI security threat. Read about Adversarial Attack →

Agent Harness

Agents & tools

The scaffolding around an LLM — tools, memory, loops, and orchestration — that turns a model into an agent. Read about Agent Harness →

Agent Orchestration

Agents & tools

The coordination layer that decides which agent or tool runs next, manages state across steps, and handles failures in multi-step AI workflows. Read about Agent Orchestration →

Agent Swarm

Agents & tools

A group of AI agents that work together — often with different roles — to solve a problem one agent could not handle alone. Read about Agent Swarm →

Agentic AI

Agents & tools

AI systems designed to act, not just respond — they plan, use tools, and make decisions across multiple steps to complete a goal. Read about Agentic AI →

Agentic Workflow

Agents & tools

A multi-step task where an AI agent autonomously decides the steps, uses tools as needed, and works toward a goal with minimal human steering. Read about Agentic Workflow →

AI Agent

Agents & tools

Software that uses an LLM to plan and act — picking tools, taking actions, and adapting based on results to complete a user’s goal. Read about AI Agent →

AI Avatar

Modalities

A photorealistic or stylised digital character driven by AI — used for video presenters, customer service, training, and marketing. Read about AI Avatar →

AI Evaluation

Training

The structured process of measuring how well an AI model performs — accuracy, safety, cost, latency — usually with a fixed test set called an eval. Read about AI Evaluation →

AI Native

Core concepts

A product designed from the ground up around AI capabilities — as opposed to bolting AI features onto an existing app. Read about AI Native →

AI Overview

Data & retrieval

Google’s AI-generated answer summary at the top of search results — synthesised from multiple sources, replacing some traditional blue-link traffic. Read about AI Overview →

AI Wrapper

Core concepts

A product whose value is mostly a thin UI over someone else’s foundation model — often used as a critique, sometimes as a description. Read about AI Wrapper →

Autonomous Agent

Agents & tools

An AI agent that operates with minimal human oversight — making and executing decisions independently across long time horizons. Read about Autonomous Agent →

B3 entries

Benchmark

Training

A standardised test used to compare AI models on specific tasks — like coding, maths, reasoning, or following instructions. Read about Benchmark →

Bias

Safety

When an AI model's outputs systematically reflect unfair patterns from its training data — about gender, race, age, or other groups. Read about Bias →

Browser Agent

Agents & tools

An AI agent that controls a real web browser — clicking, typing, and reading pages — to complete tasks on websites that lack APIs. Read about Browser Agent →

C11 entries

Chain of Thought

Prompting

A prompting technique where you ask the AI to "think step by step" before giving an answer — usually leading to better reasoning. Read about Chain of Thought →

Chatbot

Core concepts

A program that simulates conversation with users — increasingly powered by LLMs to handle natural-language questions and tasks. Read about Chatbot →

Computer Vision

Modalities

AI that can interpret images and video — recognising objects, reading text, detecting faces, or describing scenes. Read about Computer Vision →

Context Window

Core concepts

The maximum amount of text (tokens) an AI model can read and remember at once during a single conversation. Read about Context Window →

Conversational AI

Core concepts

AI systems designed for natural back-and-forth dialogue with users — covering chatbots, voice assistants, and AI agents. Read about Conversational AI →

Copilot

Agents & tools

An AI assistant embedded directly into a workflow — like coding, writing, or design — that suggests, completes, or generates work alongside the user. Read about Copilot →

Code Generation

Modalities

Using an AI model to write source code from a natural-language description, a partial snippet, or a test. Read about Code Generation →

Code Interpreter

Agents & tools

A sandboxed code-execution tool an AI agent can call to run scripts, do math, analyse files, or generate charts on the fly. Read about Code Interpreter →

Coding Agent

Agents & tools

An AI agent specialised for writing, editing, and debugging code — usually with the ability to read your repo, run tests, and open pull requests. Read about Coding Agent →

Computer Use

Agents & tools

The capability for an AI model to control a computer the way a human does — moving the mouse, clicking, typing, reading the screen. Read about Computer Use →

Constitutional AI

Safety

An Anthropic-pioneered training method that teaches a model to critique and rewrite its own outputs against a written set of principles (a constitution). Read about Constitutional AI →

D7 entries

Deep Learning

Training

A type of machine learning that uses layered neural networks to learn complex patterns — the foundation of modern AI. Read about Deep Learning →

Deepfake

Safety

AI-generated media — usually video or audio — that convincingly impersonates a real person saying or doing something they didn't. Read about Deepfake →

Diffusion Model

Modalities

The type of AI model behind most modern image and video generators — it learns to create content by reversing a noising process. Read about Diffusion Model →

Distillation

Training

Training a smaller, cheaper AI model to mimic the outputs of a larger, more capable one — preserving most of the quality at a fraction of the cost. Read about Distillation →

Data Poisoning

Safety

An attack that corrupts a model’s training data to make it behave incorrectly — either degrading performance or installing hidden backdoors. Read about Data Poisoning →

Deep Research

Agents & tools

An AI agent feature that spends minutes (not seconds) browsing many sources, reasoning across them, and producing a long-form cited report. Read about Deep Research →

DPO

Training

Direct Preference Optimization — a simpler alternative to RLHF that fine-tunes a model directly on preference pairs, no separate reward model required. Read about DPO →

E3 entries

Embeddings

Data & retrieval

A way of converting text (or images) into lists of numbers so an AI can measure how similar two pieces of content are. Read about Embeddings →

Embodied AI

Modalities

AI that operates a physical body — usually a robot — using vision, language, and motor control to act in the real world. Read about Embodied AI →

Extended Thinking

Core concepts

A model mode where the LLM spends extra compute reasoning through a problem before answering — trading latency for quality on hard tasks. Read about Extended Thinking →

F4 entries

Few-shot Learning

Prompting

A prompting technique where you include a handful of examples in the prompt so the AI learns the pattern you want it to follow. Read about Few-shot Learning →

Fine-tuning

Training

Further training a pre-trained AI model on your own data to specialise it for a specific task or style. Read about Fine-tuning →

Foundation Model

Core concepts

A large, general-purpose AI model trained on broad data that can be adapted (via prompting or fine-tuning) to many downstream tasks. Read about Foundation Model →

Function Calling

Agents & tools

A feature that lets an AI model trigger specific functions or APIs in your app instead of just returning text. Read about Function Calling →

G5 entries

Generative AI

Core concepts

AI systems that create new content — text, images, audio, video, or code — rather than just classifying or predicting from existing data. Read about Generative AI →

GPT

Core concepts

Generative Pre-trained Transformer — the architecture behind OpenAI's models, and now used as shorthand for any LLM-powered chatbot. Read about GPT →

Guardrails

Safety

Rules and filters that constrain what an AI model can output — used to block harmful, off-topic, or non-compliant responses. Read about Guardrails →

Generative UI

Modalities

A user interface where AI generates UI elements — components, layouts, even whole pages — in response to what the user is doing or asking. Read about Generative UI →

H2 entries

Hallucination

Safety

When an AI confidently states something that is factually wrong or completely made up. Read about Hallucination →

Human in the Loop

Agents & tools

An AI workflow that pauses for a human to review, approve, or correct the model’s output at key steps — instead of running fully autonomously. Read about Human in the Loop →

I1 entry

Inference

Infra & cost

The process of running a trained AI model to generate a response — as opposed to training the model. Read about Inference →

J1 entry

Jailbreak

Safety

A prompt or technique that tricks an AI model into ignoring its safety rules and producing content it would normally refuse. Read about Jailbreak →

K4 entries

Knowledge Base

Data & retrieval

A structured collection of documents an AI system can search and quote — the source-of-truth corpus that grounds RAG and many AI agents. Read about Knowledge Base →

Knowledge Distillation

Training

Training a small "student" model to imitate a large "teacher" model — capturing most of the teacher’s capability at a fraction of the size and cost. Read about Knowledge Distillation →

Knowledge Graph

Data & retrieval

A structured representation of entities and the relationships between them — used to give AI systems explicit, queryable facts. Read about Knowledge Graph →

KV Cache

Infra & cost

An inference-time cache that stores intermediate attention computations so a model doesn’t re-process its earlier tokens on every new token. Read about KV Cache →

L3 entries

Latency

Infra & cost

The time it takes an AI model to respond to a request — from when you hit send to when the first or final word appears. Read about Latency →

LLM

Core concepts

Large Language Model — the type of AI behind tools like ChatGPT and Claude, trained to understand and generate text. Read about LLM →

LoRA

Training

Low-Rank Adaptation — a cheap way to fine-tune large AI models by training a small set of extra weights instead of the whole model. Read about LoRA →

M5 entries

Machine Learning

Core concepts

A type of AI where systems learn patterns from data rather than being explicitly programmed with rules. Read about Machine Learning →

MCP

Agents & tools

Model Context Protocol — an open standard that lets AI models connect to external tools and data sources in a consistent way. Read about MCP →

Multi-modal

Modalities

An AI model that can understand and work with multiple types of input — text, images, audio, or video — not just text. Read about Multi-modal →

Mixture of Experts

Core concepts

A model architecture that has many "expert" subnetworks but activates only a few per token — getting big-model quality at small-model inference cost. Read about Mixture of Experts →

Multi-Agent System

Agents & tools

An AI architecture where multiple agents — often with different roles, models, or tools — collaborate on a task one agent could not handle alone. Read about Multi-Agent System →

N4 entries

Natural Language Processing

Core concepts

The branch of AI focused on understanding, generating, and working with human language — covering everything from spell-check to ChatGPT. Read about Natural Language Processing →

Neural Network

Training

A computing system inspired by the brain, made up of layers of connected "neurons" that learn patterns from data — the building block of modern AI. Read about Neural Network →

No-Code AI

Core concepts

AI tools and platforms that let non-developers build AI-powered apps and workflows through visual interfaces instead of writing code. Read about No-Code AI →

Named Entity Recognition

Data & retrieval

An NLP task that identifies and labels names of people, places, organisations, dates, and other specific entities in text. Read about Named Entity Recognition →

O2 entries

OCR

Modalities

Optical Character Recognition — AI that converts text inside images, scanned documents, or PDFs into editable, searchable text. Read about OCR →

Open-weight Model

Training

An AI model whose trained weights are publicly released, so anyone can download, run, or fine-tune it themselves. Read about Open-weight Model →

P5 entries

Prompt Caching

Infra & cost

A feature that stores parts of a prompt the model has already processed, making repeat or follow-up requests much faster and cheaper. Read about Prompt Caching →

Prompt Engineering

Prompting

The practice of crafting inputs to an AI model carefully to get better, more reliable outputs. Read about Prompt Engineering →

Prompt Injection

Safety

A security attack where malicious instructions hidden in user input or external content trick an AI model into ignoring its real instructions. Read about Prompt Injection →

Post-training

Training

Everything done to a model after pretraining — fine-tuning, RLHF, DPO, safety training — to turn a raw base model into a usable product. Read about Post-training →

Pre-training

Training

The first and most expensive phase of building a model — learning language and world knowledge by predicting the next token across trillions of words. Read about Pre-training →

Q1 entry

Quantization

Infra & cost

Shrinking an AI model by storing its weights in lower-precision numbers — making it smaller, faster, and cheaper with minimal quality loss. Read about Quantization →

R7 entries

RAG

Data & retrieval

Retrieval-Augmented Generation — a technique that gives an AI model access to external documents before it answers, so it can cite real, up-to-date sources. Read about RAG →

RLHF

Training

Reinforcement Learning from Human Feedback — the training technique that teaches AI models to be helpful, harmless, and honest. Read about RLHF →

Rate Limit

Infra & cost

A cap on how many requests or tokens a user can send to an AI API in a given window — used to manage cost, capacity, and abuse. Read about Rate Limit →

ReAct

Agents & tools

An agent pattern that interleaves "reasoning" steps with "acting" steps — letting the model think out loud, take an action, observe, and reason again. Read about ReAct →

Reasoning Model

Core concepts

A model variant trained or tuned to spend more compute on internal reasoning before answering — better on math, code, and multi-step problems. Read about Reasoning Model →

Red Teaming

Safety

Deliberately trying to make an AI model misbehave — find jailbreaks, exploits, and failure modes — before adversaries do. Read about Red Teaming →

RLAIF

Training

Reinforcement Learning from AI Feedback — alignment training where another AI model, not a human, provides the preference signal used to fine-tune the target model. Read about RLAIF →

S11 entries

Speech-to-Text

Modalities

AI that converts spoken audio into written text — the technology behind voice assistants, transcription tools, and meeting recorders. Read about Speech-to-Text →

Streaming

Infra & cost

Sending an AI model's response token-by-token as it's generated, so the user sees text appear immediately instead of waiting for the full reply. Read about Streaming →

System Prompt

Prompting

The high-level instructions given to an AI model at the start of a conversation that define its role, behaviour, and constraints. Read about System Prompt →

Sandbox

Infra & cost

An isolated execution environment where AI-generated code or agent actions can run without affecting the host system. Read about Sandbox →

Sentiment Analysis

Data & retrieval

An NLP task that classifies text as positive, negative, or neutral — used at scale for reviews, support tickets, social media, and survey responses. Read about Sentiment Analysis →

Small Language Model

Core concepts

A compact language model — typically 1B to 15B parameters — designed to run cheaply, fast, or on-device while still being useful for focused tasks. Read about Small Language Model →

Structured Output

Prompting

Forcing an LLM to return data in a specific format — usually JSON matching a schema — so downstream code can parse it reliably. Read about Structured Output →

Summarization

Modalities

Compressing a longer text — a meeting transcript, an article, a chat thread — into a shorter version that keeps the key information. Read about Summarization →

Superintelligence

Core concepts

A hypothetical AI that dramatically exceeds human cognitive ability across every domain — beyond AGI on the capability scale. Read about Superintelligence →

Synthetic Data

Training

AI-generated training data — used when real data is scarce, expensive, sensitive, or simply not high-enough quality. Read about Synthetic Data →

T11 entries

Temperature

Prompting

A setting that controls how random or creative an AI model's responses are — lower values produce focused answers, higher values produce more varied ones. Read about Temperature →

Text-to-Image

Modalities

AI that generates new images from a written description — the technology behind tools like Midjourney, DALL-E, and Stable Diffusion. Read about Text-to-Image →

Text-to-Speech

Modalities

AI that converts written text into natural-sounding spoken audio — used for narration, accessibility, voice assistants, and content creation. Read about Text-to-Speech →

Text-to-Video

Modalities

AI that generates video clips from a text description — the next frontier after text-to-image, with rapidly improving quality. Read about Text-to-Video →

Tokens

Core concepts

The basic units of text that AI models read and write — roughly ¾ of a word each. Models are priced and limited by token count. Read about Tokens →

Tool Use

Agents & tools

The ability of an AI model to call external tools — like a calculator, search engine, or API — to help answer a question. Read about Tool Use →

Training Data

Training

The dataset an AI model learns from — its quality, diversity, and biases directly shape what the model can do and how well it does it. Read about Training Data →

Transformer

Training

The neural network architecture introduced in 2017 that powers nearly every modern LLM, image generator, and AI breakthrough. Read about Transformer →

Test-time Compute

Core concepts

The amount of compute spent at inference time on a single response — increased dramatically by reasoning models to improve quality. Read about Test-time Compute →

Top-k Sampling

Prompting

A decoding strategy that picks the next token only from the top K most likely candidates — trading diversity for focus. Read about Top-k Sampling →

Top-p Sampling

Prompting

A decoding strategy (also called nucleus sampling) that picks the next token from the smallest set of candidates whose cumulative probability exceeds P. Read about Top-p Sampling →

V5 entries

Vector Database

Data & retrieval

A database optimised for storing and searching embeddings (numerical representations of text or images) by similarity. Read about Vector Database →

Voice Cloning

Modalities

AI that learns to mimic a specific person's voice from a short sample, then generates new speech in that voice from any text. Read about Voice Cloning →

Vibe Coding

Core concepts

A 2025–26 coined term for writing software by chatting with an AI agent — describing the vibe of what you want and accepting whatever code it generates. Read about Vibe Coding →

Vision-Language Model

Modalities

A multimodal model that processes both images and text — letting you ask questions about an image, generate captions, or reason over visual content. Read about Vision-Language Model →

Voice Agent

Agents & tools

A real-time conversational AI you talk to — over the phone, in an app, or through a wearable — that listens, reasons, and replies in voice. Read about Voice Agent →

W4 entries

Workflow Automation

Agents & tools

AI-powered tools that chain together multiple steps — apps, APIs, and AI models — to automate end-to-end business processes. Read about Workflow Automation →

Watermarking

Safety

Embedding a hidden, machine-detectable signal in AI-generated content so it can later be identified as AI-made. Read about Watermarking →

Webhook

Infra & cost

An HTTP callback an AI service makes to your endpoint when a long-running event completes — async results, agent updates, batch jobs. Read about Webhook →

World Model

Core concepts

A model that learns to simulate how the world (or a specific environment) evolves — predicting what happens next given an action. Read about World Model →

Z1 entry

Zero-shot Learning

Prompting

Asking an AI model to perform a task with no examples in the prompt — relying entirely on its general training. Read about Zero-shot Learning →

Last reviewed September 2026 · Edited by the ToolDirectory editorial team

Vol. 4 · Issue 23 · Last reviewed 2026-09-13

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