AboutConceptsAsk a question|Copy page|View as Markdown|More actionsUnderstand what environments are, how they power evaluation, agent optimization, and training, and how the same components serve all three. Concept Highlights Each explainer below covers one foundational idea and links to deeper material. EnvironmentsWhere the concept comes from, what components make up an environment, and how environments unify the evaluate-improve loop.EvaluationHow environments are used to measure model and agent performance.TrainingPost-training techniques and how environments are used for training.Key TerminologyEssential vocabulary for agent evaluation, policy-model training, RL workflows, and NeMo Gym.