With Foreign Data Wrappers (FDW) you can access remote objects from SQL databases. This feature is part of the SQL/MED (SQL Management of External Data) specification that was added to the SQL standard.
With PostgreSQL you can make use of this great functionality. You can access different remote datasources via FDW for example an ORACLE or MySQL database, JSON- or CSV-file, sources via ODBC and even twitter.
The list of FDW is very long: https://wiki.postgresql.org/wiki/Foreign_data_wrappers
There are also Geospatial Wrappers for GDAL/OGR, GeoJSON and OpenStreetMap. You can access your geospatial data for example geopackage or OGC WFS via FDW. That is easy and great fun.
Some of the wrappers support only read others support read/write access.
The presentation will give an overview on the possibilities of Foreign Data Wrappers and show how to setup a connection to remote data using some examples with geospatial data.