# Preface

This document is the comprehensive client partner’s guide for the CEOS WGISS Connected Data Assets. The document introduces the architecture
background and required skills to be a client, the query interfaces, and an implementation outline.
Several detailed use cases about how to find collections of interest via IDN (International Directory Network) or FedEO (Federated Earth Observation) and
how to interact with the WGISS Connected Assets to obtain granules are also included in this document.

This version of the book covers the two main search interfaces supported by the Connected Data Assets:

- STAC API
- OpenSearch

Additional information:

- [IDN User Guide](https://ceos.org/ourwork/workinggroups/wgiss/access/international-directory-network)
- [FedEO User Guide](https://fedeo.ceos.org/intro.html)