What does a 'layer' represent in GIS?

A 'layer' in GIS represents a distinct set of geographic information that can be displayed and analyzed separately. In the context of GIS, layers are fundamental because they allow users to organize different types of data related to a specific geographic area. Each layer typically contains information about a particular theme or category, such as land use, transportation routes, vegetation, or population density. This separation enables users to overlay multiple layers to analyze spatial relationships and patterns effectively, facilitating better decision-making and insights.

Layers can be visualized in various formats, providing the flexibility to examine how different data sets interact with one another. For example, one might overlay a land use layer with a transportation layer to assess the impact of proposed roads on local development. By managing data in layers, GIS applications enhance the ability to perform complex spatial analysis while retaining clarity and focus on specific datasets.