Plain-language reference
AI Glossary
Understand the model, retrieval, evaluation, agent, and infrastructure terms that appear in real AI projects.
23 definitions
Agent
AgentsA model-driven system that can choose actions, call tools, and iterate toward a goal.
Agentic workflow
AgentsA constrained sequence where one or more agents plan, act, verify, and hand work between steps.
Chunking
RetrievalSplitting source material into smaller passages so it can be embedded, retrieved, or placed into context.
Context window
ModelsThe maximum number of input and generated tokens a model can handle in one request.
Embedding
RetrievalA numeric representation of content used to measure semantic similarity.
Evaluation set
EvaluationA representative collection of inputs and expected behavior used to measure an AI system.
Grounding
RetrievalConnecting a model response to supplied evidence, tools, or authoritative source material.
Guardrail
EvaluationA validation or policy layer that checks model inputs, outputs, or actions before they proceed.
Hallucination
EvaluationA fluent model response that contains unsupported or invented claims.
Inference
InfrastructureRunning a trained model to generate a prediction, classification, or response.
KV cache
InfrastructureStored attention keys and values that avoid recomputing earlier tokens during generation.
Latency
InfrastructureThe elapsed time between sending a request and receiving useful output.
LLM-as-judge
EvaluationUsing a language model to score or compare outputs against a rubric.
Modality
ModelsA kind of input or output such as text, image, audio, video, or files.
Prompt injection
AgentsInstructions in untrusted content that attempt to override the intended behavior of an AI system.
Quantization
InfrastructureRepresenting model weights with lower precision to reduce memory and often improve inference speed.
RAG
RetrievalRetrieval-augmented generation: finding relevant sources and placing them into the model context before generation.
Reranker
RetrievalA model that reorders retrieved results to put the most relevant evidence first.
Structured output
ModelsA response constrained to a known schema, such as a validated JSON object.
Temperature
ModelsA sampling control that changes how concentrated or varied token selection is during generation.
Token
ModelsA unit of text processed by a model, often a word fragment, symbol, or punctuation mark.
Tool calling
AgentsA model producing a structured request for an external function, API, or application action.
Vector database
RetrievalA store optimized for indexing embeddings and finding semantically similar items.