Topic: GIS Foundations — Map Basics, Layer Types, Symbology & Visualization

❓ Essential Question

How do maps, layers, and symbology work together to create meaningful spatial data visualizations in GIS?

⭐ Key Ideas

• GIS maps are built from layers stacked on top of each other.
• Each layer contains features with attributes (the data behind the map).
• Symbology turns attributes into visual meaning.
• Good visualization = clear patterns, accurate communication.
• These concepts are the backbone of the GIS Foundations exam.

🔑 Vocabulary

Feature — A point, line, or polygon on the map.

Layer — A collection of features + their data.

Attribute — Information about each feature (fields + values).

Symbology — How features are visually represented.

Basemap — The background map (terrain, imagery, streets).

Rendering — The method used to draw features (single symbol, color ramp, graduated symbols).

Legend — Explains the symbology.