> ## Documentation Index > Fetch the complete documentation index at: https://docs.platform.aiplanet.com/llms.txt > Use this file to discover all available pages before exploring further. # Key Concepts > The core vocabulary used across the AI Planet Platform. This page defines the terms you'll see throughout the platform and the rest of these docs. Skim it once and refer back as needed. ## Workflow A **workflow** is the thing you build on the canvas — a diagram of nodes that defines how an AI task runs from input to output. Each workflow belongs to your organization and can be edited, tested, and deployed. ## Node A **node** is a single building block on the canvas. The platform provides four node types: | Node | Purpose | | ---------------------- | ------------------------------------------------------------------------------ | | **Input** | Defines the information the workflow needs to run. | | **Agent** | An AI step configured with instructions, a model, tools, and a knowledge base. | | **Output** | The final result the workflow returns. | | **Group Orchestrator** | Coordinates multiple agents working together as a team. | Tools and knowledge bases are not separate nodes — they're configured inside an agent. ## Agent An **agent** is the core working unit of a workflow — an AI step you configure with: * **Instructions** — the system prompt that defines its role and behavior * **Model** — which AI model powers it * **Tools** — external capabilities it can call * **Knowledge Base** — content it can search Agent configurations are reusable: an Agent node on the canvas references one. ## Run A **run** is a single execution of a workflow. Every time you test in the Playground or trigger a workflow through the API, a new run is created. Each run has a status (pending, running, completed, failed, or cancelled) and a full trace of what happened. ## Thread A **thread** is a conversation session. Multiple runs can belong to the same thread, which lets an agent carry context from one message to the next — like an ongoing chat rather than a one-off question. ## Deployment A **deployment** is a published, versioned snapshot of a workflow. You edit freely on the canvas, but only a deployed version can be run by your team or called through the API. One deployment is **active** at a time — that's the version that serves traffic. ## Model A **model** is a configured AI model the platform can use to power agents. You add models under [Models](/agents-models-tools/models) and select them when configuring an agent. ## Tool A **tool** is an external capability — like sending a message or fetching data from another service — that an agent can use during a run. Some tools require a **tool connection** to a linked external account. ## Knowledge Base A **Knowledge Base** is a collection of uploaded documents that the platform indexes so agents can search them and ground their answers in your own information. ## Memory **Memory** lets a workflow retain context across the messages in a thread. It's configured at the workflow level by connecting a memory provider. ## Guardrail A **guardrail** is a workflow-level safety policy. The platform supports two types: PII detection and prompt-injection protection. ## Organization Your **organization** is the workspace that contains all your workflows, resources, and members. Members are invited with a role that determines what they can do. ## Next steps Put these concepts into practice with the Quickstart.