This is web map service (WMS) standardised by OGC standard presenting the possibility to download spatial data via view service.
You can find more at this website.
The service supports three key methods:

1.	GetCapabilities	Description	Example
2.	GetMap	Description	Example
3.	GetFeatureInfo	Description	Example

You can find more spartial data services at: geoportal.gov.pl

In case of questions please contact:
The Head Office of Geodesy and Cartography
ul. Wspólna 2
00-926 Warszawa
e-mail: gugik@gugik.gov.pl