What is GIS?
A geographic information system (GIS) is software that connects data to a map. It stores what you know about the world — assets, boundaries, measurements, events — by where it is, so you can see patterns, ask spatial questions, and make decisions a spreadsheet can't support.
The plain-language definition
Every organization already has spatial data: customer addresses, work orders, pipe inventories, field photos, delivery routes. Usually it sits in tables, where the single most useful column — where — is invisible.
A GIS puts that data on a map and keeps it connected to its records. Once data has a place, new questions become answerable: What is inside the flood zone? Which circuits run through the driest fuel? How far is every customer from the nearest crew? The answers come back as maps, numbers, and lists you can act on.
That's the whole idea. Everything else — layers, buffers, rasters, digital twins — is vocabulary for doing it precisely.
A GIS thinks in layers
A GIS organizes the world as transparent layers stacked over the same geography. Imagery on the bottom, terrain above it, then parcels, networks, and live events on top. Each layer is independent — you can query it, style it, or update it alone — but because they share a location, the GIS can compare across them.
That cross-layer comparison is the analysis: overlay the flood raster on the parcel layer and you get the list of at-risk properties. Buffer the transmission lines and intersect with canopy, and you get the trim plan. Stack, compare, decide.
Four places GIS earns its keep
The same layer-and-compare logic, applied to four very different jobs.
Government
Permit reviews check zoning, floodplain, and utility layers the moment an address is entered — instead of a reviewer opening four systems by hand.
GIS for governmentUtilities
Every pole, pipe, and circuit lives on the map with its inspection history, so outage response starts with a location instead of a search.
GIS for utilitiesTransportation
Corridor assets — signs, barriers, culverts, pavement — become a measurable digital record, and inspection becomes desk review with targeted site visits.
GIS for transportationAgriculture & Forestry
Weekly satellite imagery turns into vegetation-index maps, so input prescriptions follow this season's field conditions instead of a four-year-old soil sample.
GIS for agriculture & forestryTen GIS terms worth knowing
Enough vocabulary to read a proposal, sit in a kickoff, and know what you're being sold.
- Layer
- One themed set of geographic data — roads, parcels, imagery — drawn over the same map as other layers.
- Feature
- A single thing on a map — one hydrant, one road segment, one parcel — with a geometry and a record of attributes.
- Attribute
- A fact stored about a feature, such as a pipe's diameter, install date, or owner. Attributes are what make a map queryable.
- Vector data
- Data stored as points, lines, and polygons. Best for discrete things with edges: assets, routes, boundaries.
- Raster data
- Data stored as a grid of cells, each with a value. Best for continuous surfaces: imagery, elevation, temperature.
- Coordinate reference system
- The agreed frame that ties coordinates to real ground. Layers must share one — or be transformed — before they can be compared.
- Geocoding
- Turning text addresses into map coordinates, so a customer table becomes a customer layer.
- Buffer
- A zone of specified distance around a feature — everything within 100 feet of a gas main, for example — used constantly in analysis.
- Overlay analysis
- Combining two or more layers to find where they interact: parcels inside a flood zone, wells within a setback.
- Remote sensing
- Measuring the Earth from a distance — satellites, aircraft, drones — to produce the imagery and elevation layers a GIS analyzes.
Frequently asked questions
What does GIS stand for?
GIS stands for geographic information system: software that stores, analyzes, and displays data tied to locations on the Earth. Anything with a where — an address, a pipe, a parcel, a delivery route — can live in a GIS.
What is the difference between GIS and GPS?
GPS is a positioning system: satellites that tell a receiver where it is. GIS is an information system: software that stores and analyzes location data. A GPS receiver often supplies coordinates that a GIS then maps, analyzes, and combines with other layers.
What kind of data does a GIS use?
Two main kinds. Vector data represents discrete things as points, lines, and polygons — hydrants, roads, parcels. Raster data represents continuous surfaces as grids of cells — aerial imagery, elevation, rainfall. Most real projects combine both, plus tables of attributes describing each feature.
Who uses GIS?
Governments run permitting, emergency response, and public works on it. Utilities track networks and outages. Transportation agencies manage corridors and assets. Farms, foresters, energy developers, insurers, and logistics companies all use GIS wherever a decision depends on where something is.
Do I need to be a developer or cartographer to use GIS?
No. Modern web-based GIS runs in a browser: you upload data, drag layers onto a map, and share a link. Developers can go deeper through APIs, and cartographers can refine the output, but day-to-day analysis is point-and-click.
See GIS working on your own data
GeoGarmeux Atlas puts web mapping, spatial analytics, and data pipelines in one browser-based platform — a working GIS from your first upload.
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