> For the complete documentation index, see [llms.txt](https://arch-network.gitbook.io/arch-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://arch-network.gitbook.io/arch-documentation/fundamentals.md).

# FUNDAMENTALS

- [Introducing Arch](https://arch-network.gitbook.io/arch-documentation/fundamentals/introducing-arch.md)
- [Arch’s Signature Scheme Model (FROST + ROAST)](https://arch-network.gitbook.io/arch-documentation/fundamentals/introducing-arch/archs-signature-scheme-model-frost-+-roast.md)
- [How Arch Works](https://arch-network.gitbook.io/arch-documentation/fundamentals/introducing-arch/how-arch-works.md)
- [Bridgeless Execution](https://arch-network.gitbook.io/arch-documentation/fundamentals/introducing-arch/bridgeless-execution.md)
- [Decentralized Validation](https://arch-network.gitbook.io/arch-documentation/fundamentals/introducing-arch/decentralized-validation.md)
- [State Transitions Anchored on Bitcoin](https://arch-network.gitbook.io/arch-documentation/fundamentals/introducing-arch/state-transitions-anchored-on-bitcoin.md)
- [Minimized Trust Assumptions](https://arch-network.gitbook.io/arch-documentation/fundamentals/introducing-arch/minimized-trust-assumptions.md)
- [Step-by-Step User Journey on Arch](https://arch-network.gitbook.io/arch-documentation/fundamentals/step-by-step-user-journey-on-arch.md)
- [How It Works](https://arch-network.gitbook.io/arch-documentation/fundamentals/step-by-step-user-journey-on-arch/how-it-works.md)
- [\[UNDER CONSTRUCTION\] Getting Started](https://arch-network.gitbook.io/arch-documentation/fundamentals/under-construction-getting-started.md): Note: Arch is NOT an L2.  Arch is an execution platform on the Bitcoin base layer.