AI Words

60 words that keep coming up in AI news and lessons — each with a one-line meaning, a plain explanation and an analogy.

  • Beginnerfor everyone
  • Intermediateone layer deeper
  • Advancedwith the technical terms

Basics

The words every AI conversation starts with

9 words
  • AI

    Technology that lets computers do things that used to need a human mind.

  • Machine learning

    Depth: Beginner
    ML

    Building AI by letting the computer learn rules from examples instead of being told.

  • Deep learning

    Depth: Intermediate

    Machine learning with neural networks stacked many layers deep.

  • Neural network

    Depth: Intermediate
    artificial neural network · ANN · neural net

    Layers of simple multiply-and-add units wired together: the backbone of modern AI.

  • Model

    Depth: Beginner
    AI model

    The trained core of an AI: a big bundle of numbers that turns an input into an answer.

  • Training

    Depth: Beginner
    model training

    Showing a model examples and nudging its numbers each time it gets one wrong.

  • Inference

    Depth: Intermediate
    model inference · running a model

    Running a finished, trained model to get an answer out of it.

  • Dataset

    Depth: Beginner
    training data

    A collection of examples gathered to teach or test an AI.

  • Parameter

    Depth: Intermediate
    weights · parameter count

    One of the many numbers inside a model that get tuned during training.

Language models

How chatbots read and write

15 words
  • language model

    A big AI model trained on huge amounts of text that writes by picking the next token.

  • Token

    Depth: Beginner

    The small piece of text an AI reads and writes, one at a time.

  • Tokenizer

    Depth: Intermediate
    tokenization · BPE · byte pair encoding

    The tool that chops text into tokens and gives each piece an ID number.

  • Next-token prediction

    Depth: Beginner
    next-word prediction · autoregressive generation

    Guessing the one token that comes next, based on all the text so far.

  • Context window

    Depth: Beginner
    context length · context size

    How much text an AI can read and keep in view at once, counted in tokens.

  • Temperature

    Depth: Intermediate
    sampling temperature

    A setting that controls how adventurous an AI is when picking the next token.

  • Prompt

    Depth: Beginner
    prompting · prompt engineering

    Whatever you give an AI to work with: your question, instructions and examples.

  • Hallucination

    Depth: Beginner
    AI hallucination · confabulation

    When an AI confidently says something false or made up as if it were true.

  • Transformer

    Depth: Intermediate
    transformer model · Attention Is All You Need

    The neural network design behind most of today's large language models.

  • Attention

    Depth: Advanced
    self-attention · attention mechanism

    The calculation that decides how much each token focuses on every other token.

  • Embedding

    Depth: Intermediate
    vector · embedding vector · vector embedding

    A list of numbers that captures the meaning of a word, a sentence or an image.

  • Pretraining

    Depth: Intermediate
    base model

    The first, giant training stage where a model learns broadly from huge amounts of data.

  • Fine-tuning

    Depth: Intermediate

    Extra training that shapes an already-trained model for a specific job or style.

  • RLHF

    Depth: Intermediate
    reinforcement learning from human feedback · human feedback training

    Training an AI on people's choices about which of two answers is better.

  • Generative AI

    Depth: Beginner
    GenAI

    AI that creates new things: text, images, audio or video.

What AI can do

What today's AI does, and how

12 words
  • Multimodal

    Depth: Beginner
    multimodal AI · multimodal model

    Describes an AI that handles more than text: images, sound and video too.

  • Reasoning model

    Depth: Intermediate
    thinking model · reasoning LLM

    An AI trained to work through a problem step by step before it answers.

  • Chain of thought

    Depth: Intermediate
    CoT · chain-of-thought prompting · step-by-step reasoning

    Getting an AI to write out its steps one by one before it gives the answer.

  • Tool use

    Depth: Intermediate
    function calling · tool calling

    An AI calling outside tools, like a calculator, search or code, to get things right.

  • AI agent

    Depth: Beginner
    agent · agentic AI · autonomous agent

    An AI that takes a goal and works through many steps on its own, using tools.

  • MCP

    Depth: Advanced
    Model Context Protocol

    An open standard for plugging AI apps into tools and data in one shared way.

  • RAG

    Depth: Intermediate
    retrieval-augmented generation

    Having an AI look up relevant documents first, then answer based on them.

  • System prompt

    Depth: Intermediate
    system message · system instructions · custom instructions

    Hidden instructions an AI app gives the model before your conversation starts.

  • Vibe coding

    Depth: Beginner

    Building software by telling an AI what you want instead of writing the code yourself.

  • Diffusion model

    Depth: Intermediate
    diffusion · denoising diffusion

    An AI that makes a picture by starting from random noise and cleaning it up step by step.

  • Speech recognition

    Depth: Beginner
    speech-to-text · STT · ASR

    AI that listens to spoken words and turns them into written text.

  • Computer vision

    Depth: Beginner
    CV · image recognition · machine vision

    The field of AI that lets computers look at images and work out what's in them.

Models & machines

Words from building and running models

8 words
  • Open-weight model

    Depth: Intermediate
    open weights · open model · open-weights model

    A model whose trained numbers (weights) are published so anyone can download them.

  • Benchmark

    Depth: Intermediate
    eval · evaluation · leaderboard

    A shared test that gives AI models the same questions so their scores can be compared.

  • Scaling laws

    Depth: Advanced
    neural scaling laws

    The observation that AI gets predictably better as models, data and compute grow.

  • Distillation

    Depth: Advanced
    knowledge distillation · model distillation

    Training a small model to copy what a big model has learned.

  • Quantization

    Depth: Advanced
    quantisation · 4-bit model · model compression

    Storing a model's numbers with less precision so it takes up less memory.

  • On-device AI

    Depth: Beginner
    edge AI · local AI · on-device model

    AI that runs right on your phone or laptop instead of on a faraway server.

  • GPU

    Depth: Beginner
    graphics card · graphics processing unit · AI chip

    A chip that does huge numbers of simple calculations at once: the workhorse of AI.

  • Data center

    Depth: Beginner
    data centre · server farm

    A building packed with computers where AI is trained and run.

AI and society

Risks and rules worth knowing

9 words
  • AI safety

    Depth: Beginner
    safe AI · AI risk

    The research and safeguards that aim to keep AI from causing harm.

  • Alignment

    Depth: Intermediate
    AI alignment · value alignment

    Getting an AI to act the way people intend, in line with human values.

  • Jailbreak

    Depth: Intermediate
    jailbreaking · AI jailbreak

    Wording a request cleverly to trick an AI into breaking its own safety rules.

  • Prompt injection

    Depth: Intermediate
    indirect prompt injection · injection attack

    Hiding instructions in content an AI reads, to make it do something it shouldn't.

  • Deepfake

    Depth: Beginner
    AI-generated fake · voice clone

    A fake made with AI that convincingly copies a real person's face or voice.

  • Bias

    Depth: Beginner
    AI bias · algorithmic bias

    When an AI's answers lean one way because the data it learned from was lopsided.

  • AI watermark

    Depth: Intermediate
    watermarking · SynthID · C2PA

    A hidden mark placed in AI-made content so it can later be recognised as AI-made.

  • AGI

    Depth: Beginner
    artificial general intelligence · general AI · strong AI

    AI that could handle almost any thinking task a person can, not just one or two.

  • AI regulation

    Depth: Beginner
    AI law · EU AI Act · AI Basic Act

    The laws and rules governments set for how AI is built and used.

Words from history

Words from the road to today's AI

7 words
  • Turing test

    Depth: Beginner
    imitation game

    A test of whether you can tell a machine from a person just by chatting with them.

  • Perceptron

    Depth: Intermediate
    Mark I Perceptron

    A 1958 artificial neuron that adjusts its own weights when it gets an example wrong.

  • Backpropagation

    Depth: Advanced
    backprop · backward propagation of errors

    Sending the error backward through a neural network to work out how to fix each weight.

  • AI winter

    Depth: Beginner

    A stretch of time when hopes for AI collapsed and funding and interest dried up.

  • ImageNet

    Depth: Intermediate
    ILSVRC · ImageNet challenge

    A huge set of over 14 million labeled photos, and the yearly contest built around it.

  • Reinforcement learning

    Depth: Intermediate
    RL

    Learning by trying things, getting rewards, and doing more of what earns them.

  • Supervised learning

    Depth: Intermediate

    Machine learning from examples that come paired with the right answers.