Glossary

Arena reuses the same words in billing, experiments, and deployments. This page defines them once so other guides do not repeat the same blurbs.

Term	Meaning
Project	Container for experiments (and pipelines on advanced projects). Sidebar: Experiments accordion lists projects.
Experiment	A training configuration: resource class, environment or dataset, algorithm, hyperparameters, optional HPO. Has a status (see Experiment statuses).
Run / training job	Work started when you click Train. Billed while compute runs.
Checkpoint	Saved model weights at a training step. Used to resume or deploy.
Agent	A deployed inference endpoint (Classic RL deployment or Advanced saved model).
Deployment	The live inference record behind an agent. Status on the Agents table: Undeployed, Pending, Deployed, Failed.
Resource class	Compute SKU (CPU/GPU, region or on-prem provider) chosen in the wizard Resources step.
Training configuration	Everything you set in the experiment wizard (resources, environment, agent, training, HPO). Must be complete before Train is available.
Classic RL project	Default project type: gym environments and standard RL algorithms.
Advanced project	Advanced flag on project: datasets, LLM algorithms, pipelines tab.
Organization (org)	Billing and data boundary. Users can belong to multiple orgs and switch the active one.
Credits	Usage currency for training and storage; plans include monthly allotments.
ARENA_API_KEY	Personal access token for the Arena CLI (arena_pat_… prefix). Created on Profile and CLI keys.