> For the complete documentation index, see [llms.txt](https://docs.etiq.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.etiq.ai/etiq-1.x-documentation/key-concepts.md).

# Key Concepts

- [Snapshot](https://docs.etiq.ai/etiq-1.x-documentation/key-concepts/snapshot.md)
- [Scan](https://docs.etiq.ai/etiq-1.x-documentation/key-concepts/scan.md)
- [Config](https://docs.etiq.ai/etiq-1.x-documentation/key-concepts/config.md): Configuration file description
- [Custom Tests](https://docs.etiq.ai/etiq-1.x-documentation/key-concepts/custom-tests.md): How to set up your own metrics to run regular scans and RCA type scans