How is a polygon best defined in GIS?

In Geographic Information Systems (GIS), a polygon is best defined as a set of vertices that forms a closed shape. This is foundational to understanding how spatial features are represented in GIS. A polygon is characterized by its multiple sides (or edges), where each side is defined by a pair of coordinates, known as vertices.

When a set of vertices is connected and forms a closed shape, it creates a distinct area that can represent various geographic features, such as lakes, land parcels, or administrative boundaries. The closure of the shape is essential since it demarcates the area contained within the polygon, differentiating it from line or point features in GIS.

This definition aligns well with GIS data structures, where polygons are utilized to store and analyze spatial data pertaining to areas within geographic boundaries. The concept of vertices forming a closed shape is critical for spatial analyses, such as calculating area, performing overlay operations, and executing spatial queries.

Other definitions, such as a continuous area with no boundaries or a collection of points, do not accurately reflect the nature of polygons in GIS, which must have defined boundaries and specificity in shape to be functionally useful in spatial analysis.