Glossary
Plain-language definitions of AI terms. Tap a letter to jump, or scroll the full table.
Plain-language definitions of AI terms. Tap a letter to jump, or scroll the full table.
| Term | Definition |
|---|---|
| Activation Function | A nonlinear function applied to a neuron's weighted sum that lets neural networks learn complex patterns. Common examples include ReLU, sigmoid, and tanh. |
| Adversarial Attacks | Deliberate, often small, perturbations to input data designed to fool a machine-learning model into making incorrect predictions. They expose vulnerabilities in models and are a key concern for AI robustness and security. |
| Affine Functions | Functions of the form f(x) = Wx + b that combine a linear transformation with a translation. They are the mathematical building blocks of linear layers in neural networks. |
| Agent | An AI system that can perceive its environment, reason, and take actions autonomously to achieve a goal. Modern agents often combine language models with tools and memory. |
| AI Alignment | The field of ensuring an AI system's goals and behavior reliably match human values and intentions. It is central to building safe and beneficial advanced AI. |
| AI Safety | The discipline of preventing AI systems from causing harm, whether through accidents, misuse, or unintended behavior. It spans technical robustness, alignment, and governance. |
| Algorithmic Fairness | The study and practice of designing algorithms that avoid unjust discrimination across groups defined by attributes like race, gender, or age. |
| Artificial Intelligence (AI) | The field of computer science devoted to building machines that can perform tasks requiring human-like intelligence, such as reasoning, perception, and learning. |
| Autoencoders | Neural networks that learn to compress input data into a compact representation and reconstruct it, useful for dimensionality reduction, denoising, and anomaly detection. |
| Backpropagation | The core algorithm for training neural networks that computes gradients of the loss with respect to weights via the chain rule and propagates them backward. |
| Batch Normalization | A technique that normalizes the inputs of each layer within a mini-batch to stabilize and accelerate neural-network training. |
| BERT (Bidirectional Encoder Representations from Transformers) | A transformer-based language model that reads text in both directions to build deep contextual word representations, revolutionizing NLP tasks. |
| Bias Mitigation | Methods applied to data, models, or decisions to reduce unfair bias and improve fairness across demographic groups. |
| Bias-Variance Tradeoff | The balance between a model's tendency to oversimplify (bias) and its sensitivity to noise in training data (variance); good models minimize total error from both. |
| BitNet | A family of 1-bit large language models (such as BitNet b1.58) that use ternary or binary weights to drastically cut memory and compute while preserving accuracy. |
| Chain-of-Thought Prompting | A prompting technique that encourages a model to generate intermediate reasoning steps, improving performance on complex math and logic problems. |
| Checkpoints | Saved snapshots of a model's weights and training state at a point in time, allowing training to resume or the model to be reused and deployed. |
| Computational Creativity | The study and development of AI systems that exhibit behavior deemed creative in domains such as art, music, literature, and design. |
| Compute-Efficient AI | Approaches, such as sparse models and quantization, that achieve strong performance while reducing the computational cost of training and inference. |
| Contrastive Divergence | An approximation algorithm used to train energy-based models like Restricted Boltzmann Machines by comparing data and generated samples. |
| Contrastive Learning | A self-supervised method that learns representations by pulling similar examples together and pushing dissimilar ones apart. |
| Convolutional Neural Networks (CNNs) | Neural networks using convolution operations to efficiently process grid-structured data like images, excelling at vision tasks. |
| Data Augmentation | Techniques that artificially expand a training set by transforming inputs (e.g., cropping, rotating, or paraphrasing) to improve generalization. |
| Deep Learning (DL) | A branch of machine learning using multi-layer neural networks to learn hierarchical representations from large amounts of data. |
| Diffusion Models | Generative models that learn to reverse a gradual noising process, producing high-quality images, audio, and other data from random noise. |
| Domain Adaptation | A transfer-learning technique that adapts a model trained on one distribution (source) to perform well on a related but different distribution (target). |
| Edge Devices | Small, often battery-powered computing devices (phones, sensors, IoT hardware) that run AI models locally rather than in the cloud. |
| Embedding | A list of numbers representing a piece of text's meaning, so similar texts sit close together in vector space. |
| Embedding Space | The geometric space in which embeddings live, where proximity reflects similarity in meaning or function. |
| Ethical AI | The practice of designing, deploying, and governing AI in ways that respect human rights, fairness, accountability, and societal well-being. |
| Explainability | The degree to which a human can understand the reasons a model produced a particular output. |
| Explainable AI (XAI) | Techniques and tools that make AI decisions transparent and interpretable to users, regulators, and developers. |
| Feature Engineering | The process of selecting, transforming, or creating input variables to improve a model's predictive performance. |
| Federated AI | AI systems that coordinate learning across many decentralized devices or organizations while keeping raw data local. |
| Federated Learning | A training approach where models are updated on-device and only the updates are shared centrally, preserving data privacy. |
| Feedforward | A network architecture where information flows in one direction from input to output with no cycles or feedback loops. |
| Few-Shot Learning | A model's ability to learn a new task from only a handful of examples, often by leveraging prior knowledge or in-context examples. |
| Few-Shot Prompting | Providing a language model with a few illustrative examples inside the prompt so it can infer the desired task without weight updates. |
| Fine-tuning | Further training a pretrained model on a narrow dataset so it adopts a style or specialty. |
| Generative Adversarial Networks (GANs) | A framework where a generator and discriminator compete, enabling the synthesis of realistic images, audio, and other data. |
| Generative AI | AI systems that create new content such as text, images, audio, or video, typically by learning the underlying distribution of training data. |
| GPT (Generative Pre-trained Transformer) | A family of decoder-only transformer models pre-trained on vast text corpora and fine-tuned for language generation and instruction following. |
| Gradient Descent | An optimization method that iteratively adjusts parameters in the direction opposite their gradient to minimize a loss function. |
| Hallucination | Confidently wrong output — the model fills gaps with plausible text instead of saying "I don't know." |
| Hyperparameter | A configuration setting chosen before training (such as learning rate or batch size) that controls how a model learns. |
| Knowledge Distillation | Training a smaller "student" model to mimic a larger "teacher" model, transferring capability while reducing size and cost. |
| Latent Space | The compressed, abstract representation space a model learns, where each point corresponds to a possible input or concept. |
| LoRA (Low-Rank Adaptation) | A parameter-efficient fine-tuning method that injects small trainable rank-decomposition matrices, avoiding updates to all original weights. |
| Loss Function | A function that quantifies how far a model's predictions are from the true targets, guiding the learning process. |
| LSTM (Long Short-Term Memory) | A type of recurrent neural network with gating mechanisms that captures long-range dependencies in sequential data. |
| Machine Learning (ML) | A subset of AI where systems improve at tasks by learning patterns from data rather than through explicit programming. |
| Meta-Learning | Learning algorithms that improve their own learning process, sometimes called "learning to learn," across many tasks. |
| Model | The learned function that turns input (text, image) into output. Training fixes its weights; inference just runs it. |
| Model Compression | Techniques such as pruning, quantization, and distillation that shrink models for faster, cheaper deployment. |
| Model Distillation | A form of knowledge distillation in which a compact model is trained to reproduce the behavior of a larger, more capable model. |
| Multi-Modal AI | AI systems that process and relate information across multiple modalities such as text, images, audio, and video. |
| Named Entity Recognition (NER) | An NLP task that identifies and classifies entities such as names, organizations, and locations within text. |
| Natural Language Processing (NLP) | The field of enabling computers to understand, generate, and manipulate human language. |
| Neural Networks | Computational models inspired by the brain, composed of layers of interconnected nodes that learn mappings from inputs to outputs. |
| Optimizer | The algorithm (such as Adam or SGD) that updates model weights using gradients to reduce the loss during training. |
| Overfitting | When a model learns training-data noise rather than the underlying pattern, performing well on training data but poorly on new data. |
| Perceptron | The simplest type of neural unit that computes a weighted sum and applies a step function, foundational to neural-network theory. |
| Post-Training Quantization (PTQ) | Converting a trained model's weights to lower-precision formats after training to reduce size and speed up inference. |
| Precision | A classification metric measuring the share of positive predictions that were actually correct (true positives divided by all positive predictions). |
| Prompt Engineering | The craft of designing input prompts to reliably steer a language model toward desired outputs. |
| Prompt Injection | An attack that embeds malicious instructions inside text a model processes, hijacking its behavior or bypassing safeguards. |
| Prompt Tuning | A parameter-efficient method that prepends trainable soft-prompt vectors to a frozen model instead of retraining its weights. |
| Pruning | Removing unimportant weights or neurons from a model to make it smaller and faster with minimal accuracy loss. |
| Quantization | Representing model weights and activations with fewer bits (e.g., 8-bit integers) to reduce memory and computation. |
| RAG | Retrieval-Augmented Generation: the model fetches relevant documents, then answers from them — reducing hallucination. |
| RAG (Retrieval-Augmented Generation) | A technique that grounds a language model's answers in retrieved external documents, improving factual accuracy and citation. |
| Recurrent Neural Networks (RNNs) | Neural networks with loops that maintain a hidden state, suited to sequential data like text and time series. |
| Regularization | Methods such as dropout and weight decay that constrain a model to reduce overfitting and improve generalization. |
| Reinforcement Learning (RL) | A learning paradigm where an agent improves by receiving rewards or penalties from interacting with an environment. |
| RLHF (Reinforcement Learning from Human Feedback) | Fine-tuning models using human preference signals to make their outputs more helpful, harmless, and aligned. |
| Self-Supervised Learning | Learning from unlabeled data by generating supervisory signals from the data itself, such as predicting masked parts. |
| Semantic Segmentation | Assigning a class label to every pixel in an image so that objects are understood at the pixel level. |
| Semi-Supervised Learning | Training with a small amount of labeled data combined with a large amount of unlabeled data to improve performance. |
| Sparse Modeling | Representing data or models with mostly zero values, improving efficiency and interpretability. |
| Straight-Through Estimator (STE) | A trick that passes gradients unchanged through non-differentiable operations like rounding, enabling quantization-aware training. |
| Synthetic Data | Artificially generated data used to train or test models, especially when real data is scarce, sensitive, or costly. |
| Synthetic Media | Audio, images, video, or text generated or manipulated by AI, including deepfakes and other generative content. |
| Token | A chunk of text (roughly 4 characters in English) that models read and write. Pricing and context limits are counted in tokens. |
| Tokenization | Splitting raw text into tokens (words, subwords, or characters) that a model can process numerically. |
| Training | The process of adjusting a model's parameters using data and an optimization algorithm to minimize a loss function. |
| Transfer Learning | Reusing a model trained on one task as the starting point for a related task, speeding up and improving learning. |
| Transformer-Based Models | Models built on the transformer architecture, which uses self-attention to weigh relationships across an entire sequence. |
| Transformers | A neural architecture introduced in 2017 that relies on self-attention, now the backbone of most modern language and vision models. |
| Underfitting | When a model is too simple to capture the underlying pattern, performing poorly even on training data. |
| Unsupervised Learning | Learning from unlabeled data to discover structure, such as clusters or low-dimensional representations. |
| Vibe Coding | A casual, AI-assisted coding style where a developer describes intent to a language model and accepts its generated code largely by feel, with minimal manual review. |
| Zero-Shot Learning | A model's ability to perform a task or recognize a class it was never explicitly trained on, using general knowledge and instructions. |