AI Glossary

100 AI & Prompt Engineering
Terms, Explained

From tokens to transformers, chain-of-thought to RAG — every term you need to know to work effectively with AI.

What is the Glossary? A dictionary of AI and prompt engineering terms — from tokens and temperature to RAG and chain-of-thought. Each entry has a plain-English definition, real examples, and links to related terms. Use it when you hit an unfamiliar word.

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Prompting (25)Models (20)Training (15)Technical (20)Safety (10)Concepts (10)
A

Adversarial Prompting

Safety

Crafting inputs specifically designed to cause a model to behave incorrectly or unsafely.

Agent

Concepts

An AI system that autonomously plans and executes multi-step tasks using tools and environment feedback.

Agentic Workflow

Concepts

A multi-step pipeline where an AI agent plans, acts, observes, and iterates to complete a complex task.

AI Alignment

Safety

The research field focused on ensuring AI systems pursue goals and values intended by their designers.

AI Safety

Safety

The interdisciplinary field studying how to develop AI systems that are safe, reliable, and beneficial.

API

Technical

An Application Programming Interface that lets developers call AI model capabilities programmatically.

Attention Mechanism

Technical

The core transformer operation that weighs the relevance of each token to every other token in a sequence.

Autonomous AI

Concepts

An AI system capable of pursuing goals and executing long-horizon tasks with minimal human oversight.

B

Base Model

Models

A model trained only on next-token prediction over a large corpus, before any instruction tuning.

Benchmark

Concepts

A standardised test suite used to measure and compare AI model capabilities across tasks.

Bias in AI

Safety

Systematic errors in model outputs that unfairly favour or disadvantage certain groups or perspectives.

C

Chain-of-Thought

Prompting

A prompting technique that asks the model to reason step-by-step before giving a final answer.

Chat Model

Models

A model fine-tuned to handle multi-turn conversational exchanges between a user and an assistant.

Claude

Models

Anthropic's family of large language models, known for safety, long context, and instruction-following.

Closed-Source Model

Models

An AI model whose weights and training details are proprietary and not publicly released.

Code Model

Models

A language model specifically trained or fine-tuned to understand and generate programming code.

Completion Model

Models

A model that continues text from a given prefix, used before chat-style interfaces became standard.

Constitutional AI

Safety

Anthropic's technique for training helpful, harmless AI using a set of written principles as the training signal.

Content Moderation

Safety

Automated or human review of AI inputs and outputs to prevent harmful, illegal, or policy-violating content.

Context Length

Technical

The maximum number of tokens a model can handle in a single forward pass.

Context Window

Prompting

The maximum number of tokens a model can process in a single input-output interaction.

D

Dataset

Training

A structured collection of data examples used to train, validate, or evaluate a machine learning model.

Directional Stimulus

Prompting

A hint or nudge embedded in the prompt that steers the model toward a desired answer style.

DPO (Direct Preference Optimization)

Training

A training method that aligns models to human preferences without requiring a separate reward model.

E

Embedding

Technical

A dense numerical vector that represents a token, sentence, or document in a continuous semantic space.

Emergent Behaviour

Concepts

Capabilities that appear suddenly in large models without being explicitly trained for.

Evaluation

Concepts

The systematic process of measuring AI model quality, safety, and alignment against defined criteria.

F

Fairness

Safety

The property of an AI system treating individuals and groups equitably and without unjust discrimination.

Few-Shot Learning

Prompting

Providing a small number of input-output examples in the prompt to teach the model a task pattern.

Fine-Tuned Model

Models

A pretrained model whose weights have been updated on a specific dataset for a targeted task.

Fine-Tuning

Training

Continuing training of a pretrained model on a smaller, task-specific dataset to specialise its behaviour.

Foundation Model

Models

A large model trained on broad data that can be adapted to many downstream tasks.

Function Calling

Technical

A model feature that allows it to request the execution of developer-defined functions with structured arguments.

G

Gemini

Models

Google DeepMind's family of multimodal large language models, available in Ultra, Pro, and Nano tiers.

Generated Knowledge

Prompting

A technique where the model first generates relevant facts, then uses them to answer the question.

GPT-4

Models

OpenAI's large multimodal model that set the benchmark standard for general-purpose AI capability.

Grounding

Technical

Connecting model outputs to verifiable external sources to reduce hallucination and improve accuracy.

Guardrails

Safety

Programmatic constraints that prevent an AI application from producing or acting on harmful outputs.

H

Hallucination

Technical

When a model confidently generates false or fabricated information not supported by its training data or context.

I

Inference

Technical

The process of running a trained model to generate predictions or responses from new inputs.

Instruction Prompting

Prompting

Directly telling the model what to do using clear imperative commands.

Instruction Tuning

Training

Supervised fine-tuning on diverse instruction-response pairs to improve a model's ability to follow commands.

Instruction-Tuned Model

Models

A model fine-tuned on instruction-response pairs to follow natural-language directives reliably.

Iterative Prompting

Prompting

Refining a prompt through multiple rounds of feedback until the output meets requirements.

J

Jailbreak

Prompting

A prompt designed to bypass a model's safety guidelines and elicit restricted content.

L

Large Language Model

Models

A neural network with billions of parameters trained on text to understand and generate language.

Latency

Technical

The time delay between sending a request to a model and receiving its first token in response.

Llama

Models

Meta's open-weight large language model family, the dominant open-source alternative to GPT and Claude.

Logit

Technical

The raw, unnormalised score a model assigns to each vocabulary token before converting to probabilities.

LoRA (Low-Rank Adaptation)

Training

A parameter-efficient fine-tuning method that updates only small low-rank matrices injected into model layers.

M

Memory in AI

Concepts

Mechanisms that allow AI agents to store, retrieve, and act on information across interactions.

Meta-Prompt

Prompting

A prompt that instructs the model to generate or improve other prompts.

Mistral

Models

A French AI company producing efficient open-weight models that punch above their size class.

Multimodal Model

Models

A model that can process and generate across multiple data types such as text, images, and audio.

N

Negative Prompt

Prompting

An instruction that tells the model what to avoid or exclude in its output.

Neural Network

Models

A computational model loosely inspired by the brain, made of interconnected layers of weighted nodes.

O

Open-Source Model

Models

A model whose weights are publicly available, enabling local deployment, inspection, and fine-tuning.

Output Format

Prompting

Specifying the exact structure, length, or schema the model should use when responding.

P

Parameter-Efficient Fine-Tuning

Training

A family of methods that fine-tune large models by updating only a small fraction of their parameters.

Planning in AI

Concepts

The process by which an AI agent determines a sequence of actions to achieve a goal.

Positional Encoding

Technical

A mechanism that injects token position information into transformer inputs, since attention is order-agnostic.

Pretraining

Training

The initial phase of training a model on massive text data to learn general language representations.

Prompt

Prompting

The input text sent to an AI model to elicit a specific response or behaviour.

Prompt Chaining

Prompting

Passing the output of one model call as the input to a subsequent call to complete complex tasks.

Prompt Compression

Prompting

Reducing prompt length while preserving the information needed for accurate responses.

Prompt Injection

Prompting

An attack where malicious text in external data hijacks the model's instruction-following behaviour.

Prompt Template

Prompting

A reusable prompt structure with placeholders that are filled in at runtime.

Q

QLoRA

Training

A memory-efficient fine-tuning method combining quantisation with LoRA adapters.

R

RAG (Retrieval-Augmented Generation)

Technical

Augmenting model responses by retrieving relevant documents from an external knowledge base at inference time.

ReAct Prompting

Prompting

Interleaving reasoning traces and actions so a model can use tools and reflect on their results.

Reasoning

Concepts

The capacity of an AI model to derive conclusions from premises through logical or analogical inference.

Reasoning Model

Models

A model trained to perform extended internal reasoning before producing a response.

Red Teaming

Safety

Systematically testing an AI system by attempting to elicit harmful or unintended behaviours before deployment.

Reinforcement Learning from Human Feedback

Training

A training technique that uses human preference ratings to align model outputs with human values.

Responsible AI

Safety

The practice of developing and deploying AI systems ethically, transparently, and with accountability.

RLHF

Training

Shorthand for Reinforcement Learning from Human Feedback — the alignment training paradigm.

Role Prompting

Prompting

Assigning the model a persona or expert identity to shape the style and depth of its responses.

S

Scaling Laws

Concepts

Empirical relationships describing how model performance improves predictably with more compute, data, or parameters.

Self-Attention

Technical

An attention operation where a sequence attends to itself, allowing each token to gather context from all others.

Self-Consistency

Prompting

Sampling multiple reasoning paths and selecting the most common answer to improve reliability.

Softmax

Technical

A function that converts a vector of real numbers into a probability distribution summing to 1.

Streaming

Technical

Sending model output tokens to the client incrementally as they are generated rather than all at once.

Structured Output

Prompting

Constraining model generation to produce valid, machine-parseable formats like JSON or XML.

Supervised Learning

Training

Training a model on input-output pairs where the correct output is provided as a label.

Synthetic Data

Training

Training data generated by AI models rather than collected from human-created sources.

System Prompt

Prompting

A privileged instruction block sent before the conversation that sets the model's persona and rules.

T

Temperature

Prompting

A sampling parameter that controls the randomness and creativity of model outputs.

Throughput

Technical

The number of tokens or requests an inference system can process per unit of time.

Token

Technical

The basic unit of text a language model processes, roughly corresponding to a word or word fragment.

Tokenisation

Technical

The process of splitting text into tokens using a vocabulary and encoding algorithm like BPE.

Tool Use

Technical

The ability of a model to invoke external tools — APIs, code executors, search — to augment its capabilities.

Top-P (Nucleus Sampling)

Prompting

A sampling strategy that limits token selection to the smallest set covering a cumulative probability.

Training Data

Training

The corpus of examples a model learns from during its training process.

Transfer Learning

Training

Reusing a model trained on one task as the starting point for a related task.

Transformer

Models

The neural network architecture that underpins all modern large language models, based on self-attention.

Tree of Thoughts

Prompting

A framework that explores multiple reasoning branches in parallel and selects the most promising path.

U

Unsupervised Learning

Training

Training a model on raw data without human-provided labels, discovering structure autonomously.

V

Vector Database

Technical

A database optimised for storing and querying high-dimensional embedding vectors via similarity search.

Vision-Language Model

Models

A model capable of jointly reasoning over both images and text.

Z

Zero-Shot Learning

Prompting

Asking a model to perform a task it has never seen demonstrated, relying purely on instructions.

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