I like to think I'm relatively well-versed in datums, projections, and coordinate reference systems.
OpenStreetMap data is stored in WGS84 Lat/Lon (EPSG:4326). This CRS is geographic and therefore intended to store locations on a 3D globe. When I see this map what am I looking at?
Looking at Reykjavik it appears that the longitude lines are tending towards the North Pole at the Greenwhich Meridian (or maybe they planned the city in perspective view??) so I assume 0,90 is top-centre of the map.
Does this class as a projection, and if so which one?
Is there one projection that is commonly used for lat/lon data?
I have data stored in Oracle using EPSG:4326 and when rendered by GeoServer without a specified projection it also displays these characteristics.