AI glossary
Every AI term explained in plain English, the way a knowledgeable friend would over a coffee. If a word has ever made you feel out of the loop, start here.
A
- AI AgentAn AI that does not only answer you but can take actions to complete a task, such as searching the web, using other tools, and working through several steps on its own. Think of it as moving from an adviser who tells you what to do to an assistant who goes and does it. This kind of acting AI is called an AI agent.
- API(API)A way for two pieces of software to talk to each other directly, so one program can use another's features without a person clicking around. It is like a serving hatch through which one system passes requests and receives answers. This software-to-software connection is called an API, short for application programming interface.
- Artificial Intelligence(AI)Computer systems that can do things we used to think needed human intelligence, like understanding language, recognising images, or making decisions. When people say "AI" today, they usually mean tools like ChatGPT or Claude that can hold a conversation and help with everyday tasks.
C
- Chain of ThoughtAsking an AI to work through a problem step by step, showing its reasoning as it goes, rather than jumping straight to an answer. Much like a person thinking out loud, this often leads to a more accurate result. This step-by-step reasoning is called chain of thought.
- ChatbotA program you talk to in plain language, typing a message and getting a reply, as if you were messaging a person. Modern ones, powered by AI, can hold a real back-and-forth conversation. This kind of conversational program is called a chatbot.
- Context WindowThe amount of text an AI can "see" and work with at once. Think of it as the AI's working memory: everything you have said in the conversation, plus its own replies, needs to fit inside this window. Once the conversation gets very long, the earliest parts can start to fall out of view.
E
F
- Few-shot PromptingShowing an AI a small handful of examples of what you want before asking it to do the same for you. The examples act as a pattern to follow. Because you are giving a few examples, this is called few-shot prompting.
- Fine-tuningTaking a general-purpose AI that already knows a lot and giving it extra training on a narrower set of examples so it becomes better at one particular job. Think of it as an apprenticeship: a capable all-rounder learns the ropes of a specific trade. This further training is called fine-tuning.
G
H
L
- Large Language Model(LLM)The kind of AI behind tools like ChatGPT and Claude. It has read an enormous amount of text and learned the patterns in how we write, which lets it predict what words should come next. That simple-sounding trick is what lets it answer questions, write, and hold a conversation.
- Local AIAI that runs directly on your own device, such as your laptop or phone, rather than on a company's computers over the internet. Your words never leave your machine, which keeps them private. AI that works on your own hardware like this is called local AI.
M
- Machine LearningA way of getting a computer to learn patterns from lots of examples rather than being given step-by-step instructions for every situation. Show it thousands of photos of cats and it works out for itself what a cat tends to look like. This approach is called machine learning, and it sits underneath almost every AI tool you use today.
- MarkdownA simple way of adding formatting to plain text using a few easy symbols, so you can create headings, bold words, and lists without any special software. Type a hash for a heading or wrap a word in asterisks to make it bold. This lightweight formatting language is called markdown.
- Multimodal AIAI that can work with more than one kind of input, such as text, images, sound, and sometimes video, rather than text alone. You might show it a photo and ask a question about it, or have it describe a picture in words. AI that handles several formats like this is called multimodal AI.
N
O
P
- PromptWhatever you type to an AI to get it going. A prompt can be a quick question, a detailed set of instructions, or a task with examples. Think of it as the brief you hand to a very capable but very literal assistant: the clearer the brief, the better the result.
- Prompt EngineeringThe skill of writing your requests to an AI in a way that gets you better results: being clear, giving context, showing examples, and setting out what you want. It sounds technical, but it is closer to learning how to brief someone well. This craft of writing effective requests is called prompt engineering.
R
S
T
- TemperatureA setting that controls how adventurous or predictable an AI's answers are. Turn it low and the AI plays it safe, giving steady, focused responses. Turn it up and it gets more varied and creative, but also less reliable. This creativity dial is called temperature.
- TokenThe small chunks of text an AI reads and writes in. A token is roughly a short word or part of a word, so "unbelievable" might be a few tokens while "cat" is one. AI limits, like how much fits in the context window, are counted in tokens rather than words or letters.
- Training DataThe collection of examples an AI learns from before you ever use it. For a chat assistant that means a huge amount of text: books, articles, websites, and more. This body of learning material is called training data, and it shapes what the AI knows, how it writes, and where its blind spots lie.