What is GIS

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What a question!. It gives to fill an entire blog, with several hundred entries. But since intention is to explain what a GIS is to users outside the world of Geographic Information Systems. I will try to be as concise as possible.

What does the acronym GIS mean?

The acronym GIS in means Geographic Information System.

From paper to GIS.

Maps have been available since the beginning of time, the first known maps were made in the Marshall Islands with sea shells on a palm trellis. Depictions of the terrain have been found in cave paintings, and the Egyptians are supposed to have mapped on papyrus, although there are no records.

It was not until a little more than half a century B.C. that the first cartography of the known world, made by Anaximander of Miletus, appeared.

From there to the present day, we have seen everything from maps with sea monsters in the oceans to the world upside down, elongated or with a lot of deformations. This is what are called projections. Someday we will talk about it.

The birth of GIS

In the 60s, the English geographer Roger Tomlinson planned and directed the development of the Geographic Information System of Canada, which is considered the first computerized GIS in the world.

But what is a GIS? It is, according to Wikipedia, a “type of database containing geographic data (that is, descriptions of phenomena for which location is relevant), combined with software tools for managing, analyzing, and visualizing those data. In a broader sense, one may consider such a system to also include human users and support staff, procedures and workflows, body of knowledge of relevant concepts and methods, and institutional organizations.”.

Physical map with pins
Physical map with pins

This, explained in a way that is understood, is a map to whose elements data is associated. Remember those maps from the movies of murderers with colored pins, with photographs or data clicked on the map? That could perfectly be a GIS.

What happens is that this kind of use is very limited. But it was computers that allowed to give true meaning to the concept.

In a computer, a GIS consists of a map with an associated database in which each element (be it a point, a line, a polygon or a pixel of an image) corresponds to a data from that database.

Probably the most used GIS today is Google maps. Until the appearance of the first map websites of the style of Google Maps, people were not very accustomed to using maps, maximum the GPS of the car, but almost always they pulled paper maps like the Michelin Guide. And it goes that they were not lost times.

Nowadays anyone prepares their holidays with Google Maps.

Desktop GIS

Schematic of old Geographic Information System
Schematic of old Geographic Information System

The first era of GIS began with desktop GIS, at first it was more hardware than software. They started programs like ArcInfo, which required large digitizing tablets, powerful computers and huge plotters to print the maps.

ArcInfo, created by the American company ESRI, was mainly a console software where almost everything was done with a text interface, commands in terminal mode and with a poor graphic result on the screen. But with these tools huge strides were made in the world of computer-aided cartography.

GIS printed with a dot matrix printer
GIS printed with a dot matrix printer

Then came more visual tools like ArcView, which as its name suggests, were more focused on viewing maps in a simpler way.

In the late 90s came ArcGIS, which became the standard. ArcGIS is probably the GIS equivalent of Microsoft Office in the office automation world.

In fact, ESRI managed to convert its files in .shp format to standard format.

ArcMap, the main ArcGIS tool
ArcMap, the main ArcGIS tool

Of course, there have been and are other Geographic Information Systems. One of the best known, specialized more in raster analysis was Idrisi. There have also been created by research centers or official organizations such as Ilwis and gvSIG, and there were free software. Some of them were GRASS, SAGA GIS, Sextant, and all of them ended up integrating into what is now the star desktop GIS next to ArcGIS, but in its free software version: QGIS.


As the Internet and the web have evolved, Geographic Information Systems for the browser have become increasingly affordable. Initially, they were simple publications of data generated by desktop GIS on an interactive map in a web browser, as happened with ArcGIS online, the version of ArcGIS for publishing maps in web format.

But tools such as Carto or Mapbox gave a boost to this type of maps, creating absolutely spectacular map productions.

There are also free software options such as Leaflet, a javascript library for map creation that is behind many map plugins for WordPress, and that allows you to avoid the use of APIs.

We live a very interesting moment in the constant appearance of cartographic tools for both web and mobile, in which it is convenient not to get lost, but it is convenient to know.

GIS and WordPress

If we focus on the WordPress world, we will mostly find plugins for the insertion of Google Maps maps within the publications created in this famous CMS. But if we look a little further, we will find real jewels. Tools that allow you to do very interesting tasks, both to create interactive maps and to map interiors and to present data visualizations, since maps are still a part of visual analytics, very extensive, but in the background it is about presenting data with a cartographic character.

My interest is to investigate precisely in this relationship between the world of web cartography and WordPress, although I will not limit myself only to WordPress, sometimes I will investigate in other areas. I also do not want to limit myself to cartography, but I intend to investigate the visualization of data as well.

My encouragement is that this is my blog to explore everything around this world both at the user level, and at the developer level, and learn. In short, learn.

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