I am totally new to GIS development and I am trying to grasp the concept.
From my understanding the stack looks as follows (Please correct me):
Back End GIS Server: GeoServer/GeoNode/ArcGIS Server (Some of the back end servers do have their own spatial database - however, PostGIS can still be used in conjunction with them)
Back End Spatial Database (optional): PostgreSQL/PostGIS database can be used in conjunction with back end GIS server (ArcGIS for example)
Front End Library (to display the shapes/points on top of a map(Google Maps/Open Street/etc.)): Openlayers, lefletjs and GeoExt
Now I am reading about Geo-Platform and I am not sure where exactly does it fit in the above?