The AI agent glossary
Every term you will hear, defined in one sentence you can actually use.
Software that completes a task end to end, deciding the steps and using tools to act.
Large Language ModelThe model that gives an agent its language understanding and reasoning ability.
LLMShort for large language model, the reasoning core of an agent.
RAGRetrieval Augmented Generation: answering from your data, not just the model’s training.
Retrieval Augmented GenerationLooking up relevant facts from your content before answering, to stay grounded.
EmbeddingA numeric representation of text that lets an agent measure how related two things are.
Vector DatabaseStorage that finds the most relevant chunks of your knowledge quickly.
PromptThe instructions that tell an agent how to behave and respond.
Prompt EngineeringThe craft of writing instructions that get reliable results from a model.
System PromptThe always-on instructions that set an agent’s role, rules and tone.
Fine-TuningTraining a model further on your data to specialize it for a task.
Function CallingHow an agent triggers real actions in your tools by calling defined functions.
Tool UseAn agent using external systems to get work done, not just chatting.
MCPModel Context Protocol: a standard way to give agents context and tools.
Model Context ProtocolAn open standard for connecting agents to data sources and tools.
MCP ServerA service that exposes tools and data to agents over the Model Context Protocol.
Multi-Agent SystemSeveral agents coordinating, each specialized, to handle a larger job.
Agent OrchestrationCoordinating multiple agents or steps into one reliable workflow.
Agent MemoryWhat an agent remembers across a conversation or over time.
Short-Term MemoryThe context an agent holds within a single conversation.
Long-Term MemoryKnowledge an agent retains and recalls across sessions.
Context WindowHow much text a model can consider at once when responding.
TokenThe unit of text models process; usage and limits are measured in tokens.
TemperatureA setting that controls how varied or predictable a model’s output is.
HallucinationWhen a model states something false with confidence; RAG and guardrails reduce it.
GuardrailsRules that keep an agent safe, on-topic and honest.
GroundingTying an agent’s answers to real source data so they can be verified.
ReasoningThe model’s ability to break a problem into steps and work through it.
PlanningHow an agent decides the sequence of actions to reach a goal.
Chain of ThoughtA prompting approach where the model reasons step by step before answering.
ReActA pattern where an agent alternates reasoning and taking actions.
Autonomous AgentAn agent that can pursue a goal with minimal step-by-step human input.
Human in the LoopKeeping a person in control of key decisions an agent makes.
Speech to TextTurning a caller’s voice into words the agent can read.
STTSpeech to text, the input side of a voice agent.
Text to SpeechTurning the agent’s reply into natural spoken audio.
TTSText to speech, the output side of a voice agent.
Voice AIAgents that hold natural spoken conversations over the phone or app.
Natural Language ProcessingThe field of getting computers to understand human language.
NLPShort for natural language processing.
Natural Language UnderstandingWorking out what a user actually means, beyond the literal words.
IntentWhat the user is trying to accomplish in a message or call.
EntityA specific detail an agent extracts, like a date, name or amount.
OCROptical character recognition: reading text from scanned documents and images.
Document AIReading, understanding and extracting data from real-world documents.
Computer VisionGetting models to interpret images and video.
Knowledge BaseThe collection of documents an agent answers from.
Knowledge GraphA connected map of facts and relationships an agent can reason over.
ChunkingSplitting documents into pieces so they can be embedded and retrieved.
Semantic SearchFinding results by meaning rather than exact keyword match.
RerankingReordering retrieved results so the most relevant come first.
VectorA list of numbers representing the meaning of a piece of content.
LatencyHow quickly an agent responds; lower is better for voice and chat.
ThroughputHow much work an agent can handle in a given time.
InferenceRunning a model to produce an output from an input.
ModelThe trained system that produces predictions or text.
Foundation ModelA large, general model that many applications build on top of.
Frontier ModelOne of the most capable current models available.
Open Source ModelA model whose weights are publicly available to run and adapt.
MultimodalA model that works with more than one type of input, like text and images.
Agentic WorkflowA process where agents take actions across tools to reach an outcome.
Workflow AutomationAutomating a multi-step process so it runs without manual work.
TriggerThe event that starts an agent or workflow.
WebhookA message one system sends another when something happens.
APIA defined way for software systems to talk to each other.
REST APIA common style of web API using standard HTTP methods.
GraphQLA query language that lets clients request exactly the data they need.
IntegrationA connection that lets an agent work inside one of your tools.
CRMCustomer relationship management software where sales and contact data lives.
Help DeskSoftware teams use to manage customer support tickets.
TicketA single customer request tracked in a help desk.
Ticket DeflectionResolving a request before it becomes a ticket for your team.
LeadA potential customer who has shown some interest.
Lead QualificationDeciding whether a lead is worth a rep’s time and routing it.
Lead ScoringRanking leads by how likely they are to convert.
PipelineThe set of deals moving toward a close.
ChurnWhen a customer stops using or paying for a product.
CSATCustomer satisfaction, often measured by a short post-interaction survey.
NPSNet promoter score, a measure of how likely customers are to recommend you.
SLAService level agreement: a promise about response time or uptime.
UptimeThe share of time a service is available and working.
DeploymentPutting an agent live so it starts doing real work.
On-PremiseRunning software inside your own infrastructure rather than a vendor’s cloud.
Private CloudA cloud environment dedicated to one organization.
VPCVirtual private cloud: an isolated section of a cloud provider you control.
Data ResidencyControl over which region your data is stored and processed in.
EncryptionEncoding data so only authorized parties can read it.
Encryption at RestProtecting stored data by keeping it encrypted on disk.
Encryption in TransitProtecting data while it moves between systems.
SSOSingle sign-on: logging in once to access many systems.
SAMLA standard that enables single sign-on between systems.
RBACRole-based access control: permissions based on a user’s role.
Audit LogA record of actions taken, used for review and compliance.
SOC 2A security compliance standard covering how a company handles data.
GDPREuropean data-protection law giving people rights over their data.
HIPAAUS law governing the privacy and security of health information.
PCI DSSSecurity standards for handling payment card data.
DPAData processing agreement: a contract on how a vendor handles your data.
Sub-processorA third party a vendor uses to help deliver its service.
PIIPersonally identifiable information about an individual.
PHIProtected health information covered by HIPAA.
Data MinimizationCollecting and using only the data you actually need.
Responsible AIBuilding and using AI in ways that are safe, fair and accountable.
AI GovernanceThe policies and controls that keep AI use responsible and auditable.
BiasSystematic unfairness in a model’s outputs.
ExplainabilityHow well you can understand why a model produced an output.
EvaluationTesting an agent’s quality against known cases.
BenchmarkA standard test used to compare models or agents.
Guard ModelA model that checks another agent’s output for safety or policy.
Rate LimitA cap on how many requests can be made in a time window.
Batch ProcessingHandling many items together on a schedule rather than one at a time.
StreamingReturning an agent’s response progressively as it is produced.
Sentiment AnalysisDetecting the emotional tone of a message.
SummarizationCondensing long content into the key points.
ClassificationSorting inputs into categories, like routing a ticket.
ExtractionPulling structured fields out of unstructured text.
PersonalizationTailoring an agent’s responses to the individual user.
EscalationHanding a conversation to a human when the agent should not proceed.
HandoffPassing a conversation to a person with the full context.
Knowledge CutoffThe date after which a base model has no built-in knowledge.
Prompt InjectionAn attack that tricks an agent into ignoring its instructions.
SandboxAn isolated environment where an agent can act safely for testing.
Cost per ConversationWhat it costs to run one full agent interaction.
Time to ValueHow quickly a deployed agent starts delivering results.