Today, people around the world are celebrating GIS Day. Since 1999, this distinction has been given to the Wednesday of Geography Awareness Week, which itself has been observed the third week of November for more than 25 years, supported by National Geographic. According to its official webpage, GIS Day “provides an international forum for users of geographic information systems technology to demonstrate real-world applications that are making a difference in our society.”

But these days, what is GIS? What is it NOT? Are there boundaries on what dimensions of the increasingly multi-faceted, rapidly-evolving technology are valid to celebrate today? Of course we know GIS isn't GPS — which, by the way, has its own dedicated day during National Surveyors Week — but at one time or another, you’ve tried explaining GIS to your neighbor, or uncle, mother-in-law, mail carrier, academic dean, cable guy, primary care attendant, person next to you on an airplane, etc., and they’ve heard "GPS" instead, or at least their brain made a leap to that more familiar acronym. Did you take offense and shout at them for their obvious ignorance? No, of course not. You patiently explained that GPS and GIS are two very different things, but how, with GIS, one can readily map the data that GPS provides because the two technologies play well together. See, wasn’t that easier than yelling?

Patience is a key word. Impatience earns us little or nothing, particularly when we add in a touch of condescension or disbelief. 'Really?! You don’t know what GIS is, even though it’s a multi-billion dollar global industry that supports hundreds of thousands of operations around the world each day?' If GIS were to instantly and entirely vanish off the face of the earth in this single moment, air traffic controllers could misdirect planes, ships might bump in ports, cities could lose electricity, and disaster victims would wait even longer for humanitarian aid — not to mention that the package you just mailed might never reach its destination, your children might be left off the school bus route, and if you were looking for a donut store in Redlands, California, you might have to wander for a while. But if GIS is news to you, you’re not alone.

Could GIS be the biggest technology that, on its own and in its support of other technologies, most people know nothing about?

How we talk about GIS depends on whom we’re talking with, and how quickly and accurately we perceive their prior knowledge about computers, databases, maps and how the world works. Having effective examples, similes and metaphors on hand can help sustain much more interesting dialogues. Here are some that I’ve collected over the years from fellow GIS colleagues and corroborated with other like-minded conversations that may help a novice audience, grouped into some general categories:

Digital Mapping

Computer-based maps that can show patterns and relationships across everything that’s being displayed.

It’s like Google Earth or Google Maps, except you can ask complex questions and do sophisticated analyses. So Google Earth is like GIS lite.

“Mapping” — knowing it’s not the end goal of what we are about and an oversimplification, but it’s a single, understandable word that at least gets to some of our core theme.

Mixing Maps and Data

It’s like combining a drawing package, like Adobe Illustrator, Canvas, etc., with spreadsheet software like Excel.

Mapping with spreadsheets.

“Smart maps” that you can click on, interact with and ask questions of.

The beauty of a map; the power of a database.

Layers

It’s like taking a topo map and separating out all of the different features and elements, so that the roads, the buildings, the rivers and the contour lines are all separate layers. Then you can ask questions about any one layer or across layers. (As you’re saying this, move your hands, palms down, in an alternating stacking motion, like the Macarena dance performed incorrectly.)

Information System

Did you know that A LOT of the information in the world has a geographic component? (Maybe it’s even as much as 80%, but don’t quote me.) With GIS you can represent any of that tabular information by its location, and then query and analyze it.

Simple and Effective Examples (conceptual, actual, historical, or otherwise)

John Snow and his 1854 map of cholera in London.

The questions you could ask as you are looking at a map that has crime locations marked with pins.

A global map that depicts how coastal areas are affected by sea level rise of varying amounts.

How your car’s navigation system knows how to re-route you if there is traffic congestion or detours.

The patterns that could be seen if all of the Walmarts — or another large national chain store — in the United States were to display their sales volumes for guns, or organic vegetables, snow tires, sports teams’ paraphernalia, etc.

The red and blue maps shown on presidential election night in the US, and how the commentators show what has changed since the last election.

Any explanation of how and why “location, location, location” actually matters in many diverse situations.

So if talking about GIS is something that you avoid doing because you don’t know where to start, take one of these suggestions and make it your goal this week to share your knowledge with at least one new person. Don’t worry if it doesn’t happen on Wednesday; mapping activities are taking place all week, including the events that OpenStreetMap is hosting. In fact, we’re actually in the middle of the International Map Year, so the opportunities just keep coming.

Thanks to Diane A., Jamie C., Jon C., David D., Joe F., Prabhat G., Mike G., Bill H., Rhonda H., Elizabeth K., Joseph K., Janet M., Bill M. and Bob S. for sharing their ideas and examples with me.