> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/ai-evals/core-concepts.md).

# Core Concepts

- [Core Concepts](https://developer.harness.io/ai-evals/core-concepts/concepts.md): Understand the building blocks of Harness AI Evals, including targets, datasets, metrics, evaluations, and suites.
- [Targets](https://developer.harness.io/ai-evals/core-concepts/targets.md): Understand the three target types in AI Evals and how to configure each one.
- [Datasets](https://developer.harness.io/ai-evals/core-concepts/datasets.md): Learn how to structure golden test cases and design datasets for effective AI evaluations.
- [Metrics](https://developer.harness.io/ai-evals/core-concepts/metrics.md): Explore the 47+ built-in metrics across 9 categories and learn when to use each one.