Raster vs Vector: The Two Fundamental Data Types in GIS
Every piece of spatial data in GIS falls into one of two fundamental categories. Understanding the difference between raster and vector data is not academic trivia, it directly explains why an orthomosaic behaves differently from a boundary drawing, and why certain analyses only work with one type or the other.
Raster data stores information as a grid of cells or pixels, each holding a value. Orthomosaics, DEMs, and satellite imagery are all raster formats, essentially images where each pixel represents color, elevation, or another measured value.
2 types
Fundamental spatial data categories
Zero
Vector data has no pixel resolution limit
100%
Orthomosaics and DEMs are raster format
3 shapes
Vector geometry: point, line, polygon
Practical Comparison
| Aspect | Raster | Vector |
|---|---|---|
| Storage method | Grid of cells with values | Coordinates defining exact shapes |
| Scaling behavior | Pixelates when zoomed in too far | Remains sharp at any zoom level |
| Best for | Continuous data (imagery, elevation) | Discrete features (boundaries, roads) |
| File size behavior | Grows with area and resolution | Grows with number of features |
How Survey Deliverables Split Between the Two
Typical Raster Deliverables
Typical Vector Deliverables
Boundary drawings, contour lines, utility feature files, and topographic DWG drawings are vector format.
Most real projects combine both, raster imagery as a visual background with vector features overlaid precisely on top.
Why This Distinction Matters Practically
Why can't I measure exact area from a raster image alone?
You can, but vector polygons defining exact boundaries give cleaner, more precise area calculations than tracing pixel edges on a raster image, which is why boundary and feature data is typically converted to vector format.
Can raster data be converted to vector, and vice versa?
Yes, both directions are possible. Vectorization extracts clean shapes from raster imagery, while rasterization converts vector features into a grid format, each conversion has trade-offs in precision and file characteristics.
We deliver survey data in whichever format, raster or vector, best matches your intended use, and can convert between formats as your project workflow requires. Learn more about our GIS solutions.
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