> For the complete documentation index, see [llms.txt](https://op0-2.gitbook.io/op-standard/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://op0-2.gitbook.io/op-standard/welcome-to-op.md).

# Welcome to OP

## Quick links

{% content-ref url="/pages/n1xHAv1Yo5QJYB04SZJp" %}
[Why OP?](/op-standard/overview/why-op.md)
{% endcontent-ref %}

{% content-ref url="/pages/gS3MtboAiPpLxwzDC6L8" %}
[What are Ordinals?](/op-standard/foundations/what-are-ordinals.md)
{% endcontent-ref %}

{% content-ref url="/pages/yL4sDc0bLpzFHkAxrQ8Q" %}
[What is Proof of Work?](/op-standard/foundations/what-is-proof-of-work.md)
{% endcontent-ref %}

{% content-ref url="/pages/8XKKa80MhdBEgNAXdMv4" %}
[OP-NS](/op-standard/protocols/op-ns.md)
{% endcontent-ref %}

{% content-ref url="/pages/2betIb0BtyTRmaJY8rtN" %}
[OP-20](/op-standard/protocols/op-20.md)
{% endcontent-ref %}