AI Glossary

AI Terms, Explained Simply

50+ AI and ML terms β€” from LLMs to RAG to Transformers. Plain English, no PhD required.

CoreTechnicalModelTrainingPromptingEvaluation
A

AGI

Core

Artificial General Intelligence β€” AI that can perform any intellectual task a human can. Not yet achieved.

Agent

Core

An AI system that autonomously takes actions, uses tools, and makes decisions to complete multi-step goals.

API

Technical

Application Programming Interface β€” a way for software to communicate. AI APIs let you send prompts and receive responses.

Attention Mechanism

Technical

The neural network component that allows models to focus on relevant parts of input β€” the core of Transformers.

Autoregressive

Technical

A model that generates output one token at a time, each token conditioned on all previous tokens.

B

Benchmark

Evaluation

A standardized test used to compare AI model performance (e.g. MMLU, HumanEval, HellaSwag).

C

CLIP

Model

Contrastive Language-Image Pre-training β€” OpenAI model connecting images and text, used in many image AI tools.

Chain-of-Thought

Prompting

A prompting technique where you ask the model to reason step-by-step before giving the final answer.

Context Window

Core

The maximum amount of text (tokens) an LLM can process at once. Larger = more text it can "remember" per conversation.

Constitutional AI

Training

Anthropic's method of training AI to be helpful, harmless, and honest using a set of principles.

D

Diffusion Model

Model

A type of generative AI that creates images by learning to reverse a noise-adding process. Powers Stable Diffusion, DALL-E.

DALL-E

Model

OpenAI's image generation model. DALL-E 3 is integrated into ChatGPT Plus.

E

Embedding

Technical

A numerical vector representation of text/images that captures semantic meaning. Used in search and RAG systems.

Emergent Behavior

Core

Abilities that appear in large models that were not explicitly trained β€” like multi-step reasoning, coding, or translation.

F

Few-Shot Learning

Prompting

Providing a few examples in the prompt to guide the model's output style or format without retraining.

Fine-tuning

Training

Further training a pre-trained model on a specific dataset to specialize it for a particular task or style.

Foundation Model

Core

A large AI model trained on broad data that can be adapted for many tasks (GPT-4, Claude, Gemini, Llama).

G

GAN

Model

Generative Adversarial Network β€” two networks (generator vs discriminator) competing to create realistic outputs.

GPT

Model

Generative Pre-trained Transformer β€” OpenAI's architecture. GPT-4 powers ChatGPT.

H

Hallucination

Core

When an AI confidently generates false information. A key challenge with current LLMs.

I

Inference

Technical

The process of running a trained model to generate outputs. Opposite of training.

Instruct Model

Model

A model fine-tuned to follow instructions rather than just predict the next token (e.g. GPT-4-turbo-instruct).

K

Knowledge Cutoff

Core

The date after which an LLM has no training data. Events after this date are unknown to the model.

L

Latent Space

Technical

The compressed mathematical space where AI models represent learned concepts and relationships.

LLM

Core

Large Language Model β€” an AI trained on massive text datasets to understand and generate human language.

LoRA

Training

Low-Rank Adaptation β€” efficient fine-tuning method that adds small trainable matrices without modifying the full model.

M

MoE

Model

Mixture of Experts β€” architecture where only a subset of model parameters activate per token, enabling larger models cheaply.

Multimodal

Core

AI that processes multiple types of data β€” text + images + audio + video (e.g. GPT-4o, Gemini Ultra).

Model Weights

Technical

The numerical parameters of a trained neural network. "Open weights" means you can download and run the model.

N

Neural Network

Technical

Layers of interconnected mathematical nodes inspired by the brain. The foundation of modern AI.

NLP

Core

Natural Language Processing β€” AI field focused on understanding and generating human language.

O

One-Shot Learning

Prompting

Providing exactly one example in a prompt to guide model output.

P

Perplexity

Evaluation

A measure of how well a language model predicts a text sample. Lower perplexity = better model.

Prompt

Core

The input text you give to an AI model. Quality of output heavily depends on prompt quality.

Prompt Engineering

Prompting

The practice of crafting prompts to get optimal outputs from AI models.

Q

Quantization

Technical

Reducing model precision (e.g. 16-bit to 4-bit) to run large models on consumer hardware with minimal quality loss.

R

RLHF

Training

Reinforcement Learning from Human Feedback β€” training technique where humans rate outputs to guide model behavior.

RAG

Core

Retrieval-Augmented Generation β€” combining an LLM with external knowledge retrieval to reduce hallucinations.

S

Safety Alignment

Core

Techniques to make AI behave safely and according to human values (RLHF, Constitutional AI, etc.).

Semantic Search

Technical

Search using meaning/embeddings rather than exact keyword matching. Enables much better relevance.

System Prompt

Prompting

Instructions given to an LLM before the user message β€” sets behavior, persona, and constraints.

Stable Diffusion

Model

Open-source image generation model by Stability AI. Runs locally, highly customizable.

T

Temperature

Technical

A parameter controlling output randomness. Low (0.1) = focused/deterministic. High (1.0) = creative/random.

Token

Core

The basic unit LLMs process β€” roughly 4 characters or 0.75 words. Pricing is usually per 1000 tokens.

Transformer

Model

The neural network architecture (from "Attention Is All You Need" 2017) powering most modern LLMs.

Tokenizer

Technical

The component that converts text to tokens before feeding to an LLM. Different models use different tokenizers.

V

Vector Database

Technical

A database optimized for storing and querying embeddings. Powers RAG systems (Pinecone, Weaviate, Chroma).

Vision Language Model

Model

A model that understands both images and text β€” can describe images, answer visual questions, read documents.

W

Whisper

Model

OpenAI's open-source speech-to-text model. Powers many transcription tools.

Z

Zero-Shot

Prompting

Asking a model to perform a task with no examples in the prompt β€” just instructions.

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