AI glossary

64 AI and prompting terms, each with a one-line plain-English version, a fuller definition, an example and a common mistake.

A

  • AI agent

    An AI system that can take actions toward a goal, such as searching, editing files or sending messages, not just answer questions.

  • Alignment

    The work of making AI systems pursue the goals and values their makers and users actually intend.

  • Attention (in AI models)

    The part of a transformer model that decides which other words matter most when processing each word.

C

  • Chain-of-thought prompting

    Asking the model to work through a problem step by step before giving its final answer.

  • Context engineering

    Deciding everything an AI model sees for a task: instructions, examples, documents, memory and tool results, not just the prompt wording.

  • Context window

    The maximum amount of text, measured in tokens, that an AI model can read and write in one go.

D

  • Deep research

    An AI mode that spends several minutes searching and reading many sources, then writes a detailed report with citations.

  • Delimiters

    Markers like triple quotes or XML tags that separate your instructions from the text you want the AI to work on.

  • Diffusion model

    A type of AI that generates images or video by starting from random noise and gradually refining it into a picture.

  • Distillation

    Training a smaller AI model to imitate a larger one, so you get similar results for less cost.

E

  • Embeddings

    Lists of numbers that represent the meaning of text, so a computer can find texts that mean similar things.

  • Evals (AI evaluations)

    Tests that measure how well an AI model or prompt performs on a set of example tasks.

F

  • Few-shot prompting

    Showing the model two or three examples of the task done well before asking it to do a new one.

  • Fine-tuning

    Training an existing AI model further on your own examples to change how it behaves.

  • Foundation model

    A large, general-purpose AI model trained on broad data that many different apps and tasks are built on top of.

G

  • Generative AI

    AI that creates new content, such as text, images, audio, code or video, rather than only sorting or predicting labels.

  • Generative engine optimization (GEO)

    Making your content easy for AI answer engines like ChatGPT search, Perplexity and Google AI Overviews to find, understand and cite.

  • Grounding

    Making an AI base its answer on specific sources you provide or it retrieves, instead of only its memory.

  • Guardrails

    Rules, checks and limits placed around an AI system to keep its behaviour safe and on task.

H

  • Hallucination

    When an AI model states something false or made up as if it were true.

I

  • Inference

    Running a trained AI model to get an answer. Every chat message you send triggers inference.

  • Instruction tuning

    Training that teaches a raw language model to follow instructions and answer like an assistant.

  • Iterative prompting

    Improving an AI result through a series of follow-up instructions, rather than expecting a perfect answer first time.

J

  • Jailbreak

    A prompt designed to trick an AI into ignoring its safety rules or usage policies.

K

  • Knowledge cutoff

    The date after which an AI model has no built-in knowledge, because its training data stops there.

L

  • Large language model (LLM)

    An AI model trained on huge amounts of text to predict and generate language, like the models behind ChatGPT and Claude.

  • LLM-as-a-judge

    Using an AI model to grade or compare AI outputs against criteria, instead of having people review every one.

  • llms.txt

    A plain-text file at a website’s root that tells AI tools what the site is about and which pages matter most.

M

  • Max tokens

    A setting that caps how long the AI’s reply can be, measured in tokens.

  • MCP (Model Context Protocol)

    An open standard that lets AI apps connect to tools and data sources, like a universal plug for AI integrations.

  • Meta-prompting

    Using an AI model to write, improve or critique prompts, rather than doing the task directly.

  • Multimodal AI

    AI that can work with more than one type of input or output, such as text, images, audio and video.

N

  • Negative prompt

    A list of things you do not want in an AI-generated image, such as blur, extra fingers or text.

O

  • Open-weights model

    An AI model whose trained parameters are published, so anyone can download and run it on their own hardware.

P

  • Parameters

    The internal numbers a model learns during training. Model size, like "70B", counts them in billions.

  • Prefilling

    Writing the first few words of the AI’s reply yourself, so it continues in the format you want.

  • Prompt

    The text you give an AI model to tell it what to do.

  • Prompt caching

    A feature that reuses the processed start of a prompt across requests, making repeated calls cheaper and faster.

  • Prompt chaining

    Splitting a big task into a sequence of smaller prompts, where each step uses the output of the last.

  • Prompt engineering

    Writing and testing instructions for an AI model so it reliably gives you the result you want.

  • Prompt injection

    An attack where hidden instructions in a document, email or web page trick an AI into doing something it should not.

  • Prompt template

    A reusable prompt with blanks, like {{AUDIENCE}}, that you fill in each time you use it.

Q

  • Quantization

    Storing an AI model’s numbers with less precision so it uses less memory and runs faster, with a small loss in quality.

R

S

  • Self-consistency

    Asking the same question several times, or several ways, and trusting the answer that comes up most often.

  • Semantic search

    Search that finds results by meaning, not just by matching the exact words you typed.

  • Stop sequence

    A piece of text that tells the AI to stop writing as soon as it produces it.

  • Structured output

    Getting an AI to answer in a fixed format, like JSON or a table, that software or people can use directly.

  • Sycophancy

    When an AI model tells you what you want to hear, agreeing or praising instead of being accurate or honest.

  • System prompt

    Standing instructions given to an AI model before the conversation starts, which shape every reply.

T

  • Temperature

    A setting that controls how random or predictable an AI model’s word choices are.

  • Token

    A small chunk of text, often part of a word, that AI models read and write. Usage and prices are counted in tokens.

  • Tool use (function calling)

    When an AI model asks to run a tool, like a search or a calculator, and uses the result in its answer.

  • Top-p

    A setting that limits the AI’s word choices to the most likely options that together add up to a set probability.

  • Training data

    The huge collection of text, code and other material an AI model learned from.

  • Transformer

    The neural network design behind almost all modern language models, built around a mechanism called attention.

  • Tree of thoughts

    A prompting approach where the model explores several possible paths, judges them, and continues with the most promising.

V

  • Vector database

    A database built to store embeddings and quickly find the ones most similar to a query.

  • Vibe coding

    Building software by describing what you want to an AI and accepting the code it writes, often without reading it closely.

Z

  • Zero-shot prompting

    Asking an AI model to do a task with instructions only, without showing it any examples.

Find a prompt for the task in front of you.

96 prompts in 8 categories. Copy one, fill in the blanks, paste it into any model.

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Promptlexity is a free library of 96 AI prompts and 8 downloadable AI skills across 8 categories, plus a glossary of 64 AI and prompting terms. Each prompt shows the exact text to paste, the variables to fill in, an example of what comes back, and why it works. Each glossary term has a plain-English definition, an example and a common mistake. 6 step-by-step guides cover the basics. No signup, works with ChatGPT, Claude, Gemini and other models.

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