Point, line and area features
Also called: Point, line and polygon · Topic: Remote Sensing, GIS and GNSS · NCERT: Class 12, Ch 4 "Spatial Information Technology"
Meaning
In a GIS, every real-world object on a map is stored as one of three shapes. A point marks a single spot, such as a well or a town on a small-scale map. A line is a chain of points for long, thin things, such as roads, railways and rivers. An area (or polygon) is a closed shape for things that cover ground, such as lakes, forests and districts. All three are defined by coordinates in the vector data model.
Example
On a GIS map of Rajasthan, tube wells are points, the Luni river is a line and Sambhar Lake is an area (polygon).
Don't confuse with
- Raster cells: in the raster model, everything is stored as a grid of equal squares, not as points, lines and polygons.
Related concepts
- Database management system
- Computer assisted cartography
- Spatial information technology
- Geographic information system
- Spatial data
- Attribute data
- Advantages of GIS over manual maps
- Components of GIS