> For the complete documentation index, see [llms.txt](https://archivedocs.stackstate.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://archivedocs.stackstate.com/5.1/use/concepts.md).

# Concepts

- [The 4T data model](https://archivedocs.stackstate.com/5.1/use/concepts/4t_data_model.md): StackState Self-hosted v5.1.x
- [Components](https://archivedocs.stackstate.com/5.1/use/concepts/components.md): StackState Self-hosted v5.1.x
- [Relations](https://archivedocs.stackstate.com/5.1/use/concepts/relations.md): StackState Self-hosted v5.1.x
- [Health state](https://archivedocs.stackstate.com/5.1/use/concepts/health-state.md): StackState Self-hosted v5.1.x
- [Layers, Domains and Environments](https://archivedocs.stackstate.com/5.1/use/concepts/layers_domains_environments.md): StackState Self-hosted v5.1.x
- [Perspectives](https://archivedocs.stackstate.com/5.1/use/concepts/perspectives.md): StackState Self-hosted v5.1.x
- [Anomaly detection](https://archivedocs.stackstate.com/5.1/use/concepts/anomaly-detection.md): StackState Self-hosted v5.1.x
- [StackState architecture](https://archivedocs.stackstate.com/5.1/use/concepts/stackstate_architecture.md): StackState Self-hosted v5.1.x