general CDSE links

CDSE.md

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+# The Copernicus Data Space Ecosystem (CDSE)
+
+The [Copernicus Data Space Ecosystem] (https://dataspace.copernicus.eu/) provides the largest Earth Observation (EO) data collection available to the public with discovery, download capabilities and with tools for data processing to extract and analyse those data.
+
+Each hacktahon participant should [regiter](https://identity.dataspace.copernicus.eu/auth/realms/CDSE/protocol/openid-connect/auth?client_id=cdse-public&response_type=code&scope=openid&redirect_uri=https%3A//dataspace.copernicus.eu/account/confirmed/1) for the CDSE platform where to their registered e-mails increased qutoas will be assigned. 
+
+In the CDSE the hackatrhon partipants can use: 
+ - [Copernicus Browser](https://browser.dataspace.copernicus.eu/)
+ - [JupyterLab](https://jupyterhub.dataspace.copernicus.eu/)
+ - [Data workspace](https://dataspace.copernicus.eu/workspace)
+ - [OpenEO Web Editor](https://openeo.dataspace.copernicus.eu/)
+ - [APIs](https://dataspace.copernicus.eu/analyse/apis)

CF.md

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+# Virtual servers with access to the Earth Observation data 
+
+In addition to the standard [CDSE services](CDSE.md) the hackathon participants can launch virtual server in the [CREODIAS](https://creodias.eu/)  platform provided by CloudFerro. 

README.md

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-# eubd2025_docs
-Documentation of the 2025 EU Big Data hackathon infrastructure 
+# Documentation of the 2025 EU Big Data hackathon infrastructure 
+
+The 2025 EU Big Data hackathon IT infrastructure has 2 main parts:
+
+ - [Copernicus Data Space Ecosystem](CDSE.md)  
+ - [Cloud servers](CF.md) in the [CREODIAS platform](https://creodias.eu/) provided by [CloudFerro](https://cloudferro.com/)