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// ai glossary

AI words, explained simply

Every important AI term in plain English. Bookmark this page and come back whenever you meet a new word.

Agent (AI agent)
An AI system that can plan steps and use tools (like search, email or code) to complete a goal, not just answer one message.
Example: An agent that reads new support emails, looks up the order and drafts a reply.
Algorithm
A set of steps a computer follows to solve a problem.
API
A way for one program to talk to another. Developers use AI APIs to add AI features to their own apps.
Artificial intelligence (AI)
Computers doing tasks that normally need human thinking, such as understanding language or recognising images.
Bias
When an AI's answers unfairly favour or disfavour certain people or ideas, often because of patterns in its training data.
Chatbot
A program you talk to in normal language. Modern chatbots like ChatGPT, Claude and Gemini are powered by large language models.
Context window
How much text (measured in tokens) a model can consider at once, including your messages and its replies.
Embedding
A list of numbers that represents the meaning of a piece of text, so a computer can compare meanings. Used in search and RAG.
Few-shot prompting
Giving the AI a few examples of the output you want inside your prompt.
Example: Two sample taglines, then: 'Write 3 more in this style.'
Fine-tuning
Training an existing model a bit more on your own examples so it gets better at a specific task or style.
Generative AI
AI that creates new content, such as text, images, audio, video or code.
Hallucination
When an AI states something false as if it were true, such as a made-up fact, number or source.
Inference
The moment a trained model is used to produce an answer. Each chat reply is an inference.
Large language model (LLM)
An AI model trained on a very large amount of text so it can understand and generate language.
Machine learning
Building software that learns patterns from data instead of following only hand-written rules.
Model
The trained AI 'brain' that produces outputs. Companies release different models with different strengths and prices.
Multimodal
An AI that can work with more than one type of input or output, such as text, images and audio.
Neural network
A type of machine-learning model made of many connected layers of simple maths units, loosely inspired by the brain.
Open-source model
A model whose weights are publicly released so anyone can run it on their own hardware, within its licence.
Parameters
The internal numbers a model learns during training. More parameters usually means a bigger, more capable (and more expensive) model.
Prompt
The instructions or question you give an AI.
Prompt engineering
Designing prompts on purpose so the AI gives reliable, useful results.
RAG (retrieval-augmented generation)
A method where the AI first searches your documents for relevant information, then uses it to write the answer. Reduces made-up facts.
Example: A company chatbot that answers from the official policy documents.
System prompt
Hidden instructions a developer gives a model to set its role, rules and style before the user starts chatting.
Temperature
A setting that controls how random or creative a model's output is. Low = more predictable, high = more varied.
Token
A small piece of text (often part of a word) that models read and write. Usage and limits are measured in tokens.
Training data
The examples a model learned from. Its knowledge and biases come from this data.
Vector database
A database that stores embeddings so you can quickly find text with similar meaning. Common in RAG apps.