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

# Core concepts

- [Products & Targets](https://docs.duku.ai/core-concepts/products-and-targets.md): Understand how products and targets relate.
- [Explorations & State Graphs](https://docs.duku.ai/core-concepts/explorations-and-state-graphs.md): Learn how Duku discovers states, transitions, and graphs.
- [Goals & Intent Tests](https://docs.duku.ai/core-concepts/goals-and-intent-tests.md): Understand goals, intents, and how intent tests work.
- [Issues & signals](https://docs.duku.ai/core-concepts/issues-and-signals.md): How Duku turns the errors it finds into a short list of distinct problems.
- [Visual issues](https://docs.duku.ai/core-concepts/visual-issues.md): Catch bugs your users can see on screen, even when no error is raised.