"Geographic Coordinate Systems" and "Projected Coordinate Systems" in ArcGIS and ArcMap
Let's take a look at the way ArcMap in ArcGIS understands projections. ArcMap uses things called "Geographic Coordinate Systems" and "Projected Coordinate Systems", which can be confusing because the terminology does not match what we use when we learn the theory of datums and projections. So, here is what ArcGIS means when it uses these terms. This way you can be sure you get it all correct, and can get overlay data correctly and accurately.
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