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Language changes all the time and I see various uses of the words defining the data we use in GIS in our day-to-day lives.

But what's right? Is there a right answer out there that we would all agree on or just break out into riots (or simply not care)?

We have spatial data, geodata, geospatial data, geographic data - anymore missing?

Spatial is quite generic and geospatial a bit more defining geographically spatial - but what about geodata?!

If you were writing a scientific paper about data that is spatial within the geographical and geological domains what term would you use?

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There is a good information about these terms on Basudeb Bhatta's Blog at this link, copied below.

@Brad Nesom's definitions are good but I thought that geodata was an abbreviation of "geographic data." However, Brad's definition of geodata is quite logical.

Beside these in my opinion:

spatial data > geospatial data == geographic data == geodata 

...

Often my students ask about the difference(s) between spatial and geospatial. These two words appear very frequently in remote sensing and GIS literature.

The word spatial originated from Latin 'spatium', which means space. Spatial means 'pertaining to space' or 'having to do with space, relating to space and the position, size, shape, etc.' (Oxford Dictionary), which refers to features or phenomena distributed in three-dimensional space (any space, not only the Earth's surface) and, thus, having physical, measurable dimensions. In GIS, 'spatial' is also referred to as 'based on location on map'.

Geographic(al) means 'pertaining to geography (the study of the surface of the earth)' and 'referring to or characteristic of a certain locality, especially in reference to its location in relation to other places' (Macquarie Dictionary). Spatial has broader meaning, encompassing the term geographic. Geographic data can be defined as a class of spatial data in which the frame is the surface and/or near-surface of the Earth. 'Geographic' is the right word for graphic presentation (e.g., maps) of features and phenomena on or near the Earth's surface. Geographic data uses different feature types (raster, points, lines, or polygons) to uniquely identify the location and/or the geographical boundaries of spatial (location based) entities that exist on the earth surface. Geographic data are a significant subset of spatial data, although the terms geographic, spatial, and geospatial are often used interchangeably.

Geospatial is another word, and might have originated in the industry to make the things differentiate from geography. Though this word is becoming popular, it has not been defined in any of the standard dictionary yet. Since 'geo' is from Greek 'gaya' meaning Earth, geospatial thus means earth-space. NASA says 'geospatial means the distribution of something in a geographic sense; it refers to entities that can be located by some co-ordinate system'. Geospatial data is to develop information about features, objects, and classes on Earth's surface and/or near Earth's surface. Geospatial is that type of spatial data which is related to the Earth, but the terms spatial and geospatial are often used interchangeably. United States Geological Survey (USGS) says "the terms spatial and geospatial are equivalent".

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Sometimes I might ask if the data has either temporal or location information, and then get into details about how to use it. Really this is no different than asking if a column in the database is float, decimal, or money. Significantly different to work with -- you need to know your data.

So I do not define the data as spatial or not, I simply expect to see either geography or geometry columns (or create them if need be).

Usually the collection, view, or USE CASE of the data becomes the defining term we will use, e.g. "These data are for prioritizing the underground tank clean up based on the volume and depth of the leaking hazard" or "This maps the water pressure deliverable across the city at fire hydrants."

In sum: we don't call it financial data, or monetary data, or spatial data. Its just data, sometimes with a geometry or geography column.

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Since this is a Community WIKI this is my opinion.
As for actual definitions I don't know. And how (or why J) you write a scientifc paper as well.
But what I see in my mind is this.
geospatial data, spatial data can be data in any format with any coordinate reference in any storage type.
geographic data (outside the national geographic context) is rdbms native spatially enabled lat/lon data.
geodata is any type of data as a service served by a web server.
Again I re-iterate that these are NOT definitions simply how I use the terms in context when discussing and how I think of them to keep stuff seperate. FWIW.

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Etymology vs common-use? Which is it?

  • Etymologically these words have different roots and the difference may matter in a different profession. To that extent, I'd suggest checking out English.StackExchange.
  • Professionally, we don't differentiate.

If you want to argue that we do differentiate, what happens when you call as ST_AsGeoJSON, on coordinates on the Martian SRID 49900: hint nothing special it works fine. There is no MarsJSON, and we'll never rename the spec to SpatialJSON no matter how much more proper it would be.

On DBA.StackExchange, the gis tag is a tag-synonym for spatial. And, on StackOverflow, hopefully it will be too. As far as the geo- prefix, it's just like all science that start out with arrogantly putting Earth or humans in the center and later migrates away from that model. There is nothing special about Earth. It's just a planet, and the same math defines the ellipsoids and "geoids" on other planets.

As far as geographic vs geometric data, PostGIS overloads geographic to mean Geodidic CRS. But, even the word geo-didic isn't specific to Earth anymore, from the wikipage,

is the scientific discipline that deals with the measurement and representation of the Earth (or any planet)

On Mars, it's actually called Martian Geodesy. The gravatiational readings on Mars still produce what is called a "geoid" despite the "geo" prefix.

Which term would I use? I would default to "spatial" unless I knew people smarter than myself attaching themselves to a term I found to be commonly accepted. In which case I would use that term.

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