---
title: Overview
order: 10
---

Rerun is the Unified Data Layer for Physical AI.
The Rerun SDK connects to a catalog server, which allows you to store, retrieve, and query over large amounts of data, and integrates with the SDK so you can browse and inspect the data visually.

The Rerun SDK includes a simplified open-source catalog server that is API compatible with Rerun Hub, our managed offering.
The open-source server loads everything into memory, which makes it fast and simple to operate for very small datasets, which in turn makes it perfect for quick testing and local experimentation.

See the [how-to guide for the open-source server](get-data-out.md) for more details on launching and connecting to the server.
