What is a GIS 'layer'?

A GIS 'layer' refers to a separate, distinct dataset that can be viewed and analyzed alongside other datasets within a Geographic Information System. Each layer contains specific types of information, such as roads, water bodies, or land use, allowing users to visualize and analyze spatial relationships and patterns. By layering different datasets, users can comprehend complex spatial interactions and conduct various analyses, such as overlaying population density data over geographical boundaries. This ability to combine multiple layers enhances the analytical capabilities of a GIS, enabling more informed decision-making.

In the context of GIS, visual representation and stacking images are part of how layers are utilized or displayed, but they do not encapsulate the fundamental definition of what a layer is. Layers are essentially the building blocks of GIS operations, allowing for systematic organization and analysis of spatial data.