# FUNDAMENTALS

- [Introducing Arch](/arch-documentation/fundamentals/introducing-arch.md)
- [Arch’s Signature Scheme Model (FROST + ROAST)](/arch-documentation/fundamentals/introducing-arch/archs-signature-scheme-model-frost-+-roast.md)
- [How Arch Works](/arch-documentation/fundamentals/introducing-arch/how-arch-works.md)
- [Bridgeless Execution](/arch-documentation/fundamentals/introducing-arch/bridgeless-execution.md)
- [Decentralized Validation](/arch-documentation/fundamentals/introducing-arch/decentralized-validation.md)
- [State Transitions Anchored on Bitcoin](/arch-documentation/fundamentals/introducing-arch/state-transitions-anchored-on-bitcoin.md)
- [Minimized Trust Assumptions](/arch-documentation/fundamentals/introducing-arch/minimized-trust-assumptions.md)
- [Step-by-Step User Journey on Arch](/arch-documentation/fundamentals/step-by-step-user-journey-on-arch.md)
- [How It Works](/arch-documentation/fundamentals/step-by-step-user-journey-on-arch/how-it-works.md)