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How LLMs Are Made / Glossary

How LLMs Are Made glossary

Plain-language definitions of How LLMs Are Made terms, each linked to a short visual lesson.

AI alignment
AI alignment is the work of making an AI system's behaviour match what people intend and value: helpful with everyday requests, honest about what it knows and careful to avoid harm.
AI benchmark
An AI benchmark is a fixed set of tasks with checkable answers, such as exam questions, maths problems or coding tasks, used to measure and compare how well models perform.
Attention mechanism
The attention mechanism is the part of a transformer that lets each token weigh how much every other token matters to it, then take in a mix of their information based on those weights.
Base model
A base model is a language model straight out of pretraining. It continues text instead of following instructions, so it needs further training before it works as an assistant.
Chain of thought
Chain of thought is the step-by-step working a language model writes out before its final answer. Reasoning models are trained to produce long chains of thought to solve harder problems.
Context window
A context window is the maximum amount of text, counted in tokens, that a language model can take in at once, including your messages, its replies, pasted files and hidden instructions.
Data deduplication
Data deduplication means finding and removing repeated copies of the same text from a dataset, so a language model does not see the same passage again and again during training.
Embedding
An embedding is a list of numbers that represents a word, token, sentence or image as a point in a space of meaning, so that things with similar meanings end up close together.
Fine-tuning
Fine-tuning means training an already pretrained model a little more on a smaller, focused set of examples, so it gets better at a task or behaves in a particular way.
Gradient descent
Gradient descent is the method that trains most AI models: it works out which direction lowers the loss for every weight, then nudges all the weights a small step that way, again and again.
Knowledge distillation
Knowledge distillation trains a small “student” model to copy the outputs of a large “teacher” model, so the student keeps much of the teacher's skill at a fraction of the size.
Loss function
A loss function is the formula that measures how wrong a model's prediction was. Training tries to make this number, the loss, as small as possible.
Model card
A model card is a short public document released with an AI model, like a nutrition label. It says what the model is for, how it was trained and tested, and its known limits and risks.
Parameters (model weights)
Parameters, also called weights, are the adjustable numbers inside an AI model. Training tunes them so the model's predictions get better, and together they store everything the model has learned.
Pretraining
Pretraining is the first and biggest stage of building a language model: it reads a huge amount of text and learns by predicting the next token, over and over, without any human labels.
Quantization
Quantization makes an AI model smaller and faster by storing each of its weights with fewer bits, for example 4 instead of 16, accepting a small amount of rounding error.
Red teaming
Red teaming is deliberately attacking your own AI system before release, trying to make it misbehave so its weak spots can be found and fixed before real users meet them.
Reward model
A reward model is a separate AI model that scores answers the way human raters would. It is trained on human comparisons and then used to guide a language model toward better answers.
RLHF (reinforcement learning from human feedback)
RLHF, reinforcement learning from human feedback, is a training method that teaches a model which answers people prefer, using many human comparisons between pairs of answers.
robots.txt
robots.txt is a small text file on a website that tells crawlers which pages they may and may not visit. Site owners can use it to ask AI crawlers not to collect their content.
Scaling laws
Scaling laws are patterns showing that a language model's loss falls smoothly and predictably as you add parameters, training data and compute. Labs use them to plan how big to build.
Temperature (AI)
Temperature is a setting that controls how predictable or varied a language model's output is. Low temperature makes it stick to the most likely tokens; high temperature makes less likely ones more common.
Tokenizer
A tokenizer is the tool that cuts text into tokens, the pieces a language model reads, and turns each piece into a number. It also turns the model's output numbers back into text.
Tool calling (function calling)
Tool calling is when a language model writes a structured request to use an outside tool, such as a search, calculator or calendar, and the software around it runs the tool and returns the result.
Transformer
A transformer is the neural network design behind almost all modern language models. It processes every token of a text in parallel and uses attention to let the tokens share information.
Web crawler
A web crawler is a program that visits web pages automatically, saves their content and follows their links to find more pages. Crawlers collect much of the text used to train language models.