AI CONCEPTS

Understand AI, one concept at a time.

Direct definitions connected to examples, common mistakes, technical decisions, and verified editorial analysis.

60catalogued concepts
8knowledge areas
28complete editorial entries

Fundamentals

Basic units, capabilities, and limits for understanding how an AI system works.

Models and learning

Architectures, training, and techniques that shape model behaviour.

INTERMEDIATEVerified entry

Fine-Tuning: What Changes When You Continue Training a Model—and What It Does Not Guarantee

Fine-tuning is additional training of a previously trained model to adapt it to a specific objective. This entry explains the process, walks through three examples, and distinguishes the concept from other ways of adapting or using models.

fine-tuning
ADVANCEDVerified entry

Self-Supervised Learning: What It Is and How It Works

Self-supervised learning creates training objectives from the data itself. This guide explains how the approach works, gives examples from language, vision, and audio, and clarifies its limits and how it differs from other methods.

self-supervised learning
ADVANCEDEditorial baseline

Aprendizaje por refuerzo con feedback humano

Familia de métodos que usa preferencias humanas para entrenar señales de recompensa y orientar el comportamiento de un modelo.

RLHF
INTERMEDIATEVerified entry

Synthetic Data: What It Is, How It Is Generated, and What It Does Not Guarantee

Synthetic data is generated artificially to preserve properties of real data that matter for a specific purpose. Its artificial origin does not, by itself, show that it is useful, high-quality, or private.

synthetic data
ADVANCEDVerified entry

Knowledge Distillation: How a Student Model Learns from a Teacher—and What It Does Not Guarantee

Distillation transfers training signals from a teacher model to a student. It can take different forms; it does not mean that the student preserves every capability or is more efficient in every environment.

knowledge distillation
ADVANCEDVerified entry

Loss Function: What It Measures During Training—and What It Doesn’t Tell You About a Model

A loss function quantifies the discrepancy between a prediction and a target according to a defined criterion. Understanding what it penalizes—and what falls outside that measure—helps you interpret training without mistaking it for a complete evaluation of the model.

loss function
ADVANCEDVerified entry

LoRA: How It Adapts a Model with Low-Rank Matrices—and What It Doesn’t Guarantee

LoRA adapts a pretrained model by keeping its original weights fixed and learning additional low-rank matrices. This guide explains the mechanism, compares it with other forms of adaptation, and clarifies what cannot be concluded from the number of trainable parameters alone.

Low-Rank Adaptation
ADVANCEDVerified entry

Attention Mechanism: How a Model Relates Different Parts of an Input

Attention is a mathematical operation that combines representations according to their compatibility. This guide explains Q, K, and V, the mechanism’s variants, and its limits—without confusing computational attention with human attention or treating it as an automatic explanation of a model.

attention
INTERMEDIATEVerified entry

Distilled Model: What the Label Means—and What It Does Not Prove

A distilled model is the student produced by a process that transfers some of a teacher model’s behavior. The label describes a training relationship, not a guarantee of equivalence, quality, or efficiency.

distilled model
INTRODUCTORYEditorial baseline

Modelo fundacional

Modelo entrenado a gran escala sobre datos amplios y adaptable a múltiples tareas posteriores.

foundation model
INTERMEDIATEVerified entry

Pretraining: What a Model Learns Before It Is Adapted

Pretraining is a training phase that comes before certain uses or later adaptations. Its objective, data, and relationship to other stages depend on the model: there is no universal recipe, and pretraining alone does not guarantee that a system is reliable.

pretraining
INTERMEDIATEEditorial baseline

Sobreajuste

Situación en la que un modelo se adapta demasiado a los datos de entrenamiento y pierde rendimiento ante casos nuevos.

overfitting
ADVANCEDEditorial baseline

Transformer

Arquitectura neuronal basada principalmente en atención que procesa relaciones entre elementos de una secuencia o varias modalidades.

arquitectura transformer

Generation and interaction

Concepts involved in requesting, controlling, and validating a generated response.

INTRODUCTORYEditorial baseline

Aprendizaje con pocos ejemplos

Uso de unos pocos ejemplos dentro de la petición para mostrar al modelo la tarea, el criterio o el formato esperado.

few-shot prompting
INTERMEDIATEVerified entry

In-Context Learning (ICL): How a Model Responds to Prompt Examples

In-context learning lets you guide a model’s response with instructions and examples included in its input. Learn what it means, how to test it, and how it differs from training and related methods, with examples from support, invoices, and customer reviews.

in-context learning · ICL
INTERMEDIATEVerified entry

Chain of Thought in AI: What It Is—and What It Doesn’t Prove

A chain of thought is a sequence of intermediate steps expressed in text that a model generates or receives as an example. It can help structure a task and make some steps visible, but coherence does not prove that those steps are correct or faithfully reflect the internal process that produced the answer.

chain of thought · CoT
INTERMEDIATEVerified entry

Context Engineering: How to Select and Maintain the Information an AI System Receives

Context engineering means deciding what information a model needs for a task, how to obtain it, and how to keep it relevant while the task is underway. It is not the same as writing a longer prompt: it also involves selecting documents, using tools, and managing state.

context engineering
INTRODUCTORYEditorial baseline

Prompt

Conjunto de instrucciones y contexto entregado a un modelo para orientar una tarea y su formato de salida.

instrucción · petición
INTERMEDIATEEditorial baseline

Razonamiento en modelos

Capacidad observable de combinar información, restricciones y pasos intermedios para resolver una tarea.

reasoning
INTRODUCTORYEditorial baseline

structured output

Respuesta que debe ajustarse a un esquema definido para poder validarse y procesarse de forma automática.

structured output
INTRODUCTORYEditorial baseline

Temperatura

Parámetro de muestreo que modifica la distribución de probabilidad usada para seleccionar los siguientes tokens.

temperature

Data and knowledge

How data is represented, retrieved, and connected to verifiable answers.

INTERMEDIATEVerified entry

Vector Database: What It Stores and How Similarity Search Works

A vector database stores numerical representations and retrieves those closest to a query. It does not necessarily generate embeddings or decide on its own which results are relevant.

vector database
INTRODUCTORYEditorial baseline

Búsqueda semántica

Recuperación de información basada en relaciones de significado, normalmente combinada con filtros o búsqueda léxica.

semantic search
INTRODUCTORYEditorial baseline

Embedding

Representación numérica que sitúa elementos en un espacio donde ciertas relaciones pueden medirse por proximidad.

incrustación · vector semántico
INTERMEDIATEEditorial baseline

Fragmentación de documentos

División de documentos en unidades recuperables que conservan suficiente contexto para responder preguntas.

chunking
INTRODUCTORYVerified entry

Primary Source: What It Is, How to Identify It, and What It Can Show

A source is primary in relation to a question when it presents directly the object, data, method, or decision being studied. Its status does not guarantee that it is true, impartial, or sufficient: you still need to assess what it claims and what its limits are.

primary source
INTERMEDIATEEditorial baseline

Generación aumentada por recuperación (RAG)

Patrón que recupera información externa relevante y la incorpora al contexto antes de generar una respuesta.

RAG · retrieval-augmented generation
INTERMEDIATEEditorial baseline

Grounding

Conexión de una respuesta con datos recuperados, observaciones, herramientas o fuentes externas que pueden comprobarse.

anclaje en fuentes
INTERMEDIATEVerified entry

Reranking: What It Is, How It Works, and Its Limits in Retrieval Systems

Reranking is a second scoring stage in retrieval systems that evaluates query–document pairs to refine an initial set of candidates. This glossary entry explains how it works, distinguishes two-stage retrieval from vector search alone, and examines operational limits in RAG and semantic search.

reranking

Agents and automation

Tools, memory, and patterns for systems capable of carrying out tasks.

Assessment

Methods for measuring quality, cost, robustness, and usefulness under reproducible conditions.

INTRODUCTORYVerified entry

AI benchmarks: what they measure and what a score demonstrates

A benchmark is an evaluation defined by tasks, data, a protocol, and metrics. Its score describes performance under those specific conditions; by itself, it proves neither general capability nor production performance.

banco de pruebas
ADVANCEDEditorial baseline

Contaminación de datos

Presencia total o parcial de datos de evaluación en el entrenamiento, ajuste o contexto previo de un modelo.

data contamination · benchmark leakage
INTRODUCTORYEditorial baseline

Evaluación de IA

Prueba reproducible que mide un comportamiento mediante casos, condiciones, métricas y una rúbrica explícita.

eval
INTERMEDIATEEditorial baseline

Generalización

Capacidad de mantener un comportamiento útil ante ejemplos o condiciones que no coinciden exactamente con los datos de entrenamiento.

generalization
INTERMEDIATEEditorial baseline

Incertidumbre

Grado de falta de certeza sobre una predicción, una respuesta, la evidencia disponible o la validez de una medición.

uncertainty
INTERMEDIATEVerified entry

LLM-as-a-judge: what it evaluates and which biases to check

An LLM-as-a-judge approach uses a language model to assess responses or actions against explicit criteria. This guide explains the process, distinguishes different types of judgment, and shows what to verify before relying on the results.

LLM-as-a-judge
INTERMEDIATEEditorial baseline

Reproducibilidad

Capacidad de repetir una evaluación con versiones, datos, configuración y procedimiento documentados y obtener resultados compatibles.

reproducibility
INTERMEDIATEEditorial baseline

Robustez

Capacidad de mantener un comportamiento aceptable ante variaciones, ruido, casos extremos o intentos de manipulación.

robustness
INTRODUCTORYEditorial baseline

Rúbrica de evaluación

Conjunto explícito de criterios y niveles que convierte una valoración en una puntuación interpretable y repetible.

scoring rubric

Safety and governance

Risks, controls, and responsibilities throughout the lifecycle.

INTRODUCTORYVerified entry

AI Hallucinations: What They Mean and How to Recognize an Unsupported Answer

A fluent answer is not necessarily a correct one. This guide explains what AI hallucination means, how to distinguish it from other errors, and what checks can help assess specific claims.

confabulación
INTERMEDIATEVerified entry

AI Guardrails: What They Control, Where They Act, and What They Don’t Guarantee

A guardrail is a control that checks a system’s inputs, outputs, or actions against a defined policy. Its scope depends on what it reviews and when it intervenes: it can reduce certain risks, but it cannot by itself prove that the entire system is safe.

barrera de seguridad
INTRODUCTORYVerified entry

Human-in-the-Loop (HITL): What a Person Decides—and What Their Involvement Does Not Guarantee

HITL describes a design in which a person intervenes at a defined point in an automated system. The label alone does not say what authority they have or guarantee that they will detect errors.

human in the loop · HITL
INTERMEDIATEEditorial baseline

Instruction injection

Ataque o interferencia en la que contenido no confiable intenta desviar al sistema de sus reglas u objetivo legítimo.

prompt injection
INTRODUCTORYEditorial baseline

Moderación

Clasificación y tratamiento de contenido según políticas de seguridad, uso aceptable o requisitos legales.

content moderation
INTERMEDIATEVerified entry

The Principle of Least Privilege: What It Means and How to Apply It to AI Systems

The principle of least privilege limits each identity—person, process, or service—to the permissions needed for its task. In AI systems, it guides access for agents, tools, and services, but does not replace authentication or, by itself, guarantee that a model behaves safely.

least privilege
INTERMEDIATEVerified entry

Adversarial Testing: Definition, Methodology, and Limits in AI Systems

Adversarial testing in AI is an intentional evaluation discipline that seeks to break a system's guarantees through hostile inputs or designed scenarios. This entry defines the concept, distinguishes manual practice from automation, details the technical lifecycle, and analyzes its inherent limits regarding coverage and reproducibility.

red teaming
INTRODUCTORYEditorial baseline

Supervisión humana

Capacidad efectiva de personas responsables para comprender, vigilar, intervenir y detener un sistema cuando sea necesario.

human oversight
INTRODUCTORYEditorial baseline

Verificación de hechos

Proceso de contrastar afirmaciones verificables con evidencia identificable, vigente y suficientemente autorizada.

fact-checking

Operations and infrastructure

Techniques for deploying, optimising, and observing AI systems in production.