To understand how digital maps work in web applications, you need to grasp a few core concepts: map tiles, coordinate systems, and how maps are rendered in the browser. Digital maps are typically made up of many small square images called map tiles. Each tile represents a specific geographic area at a particular zoom level. When you view a map online, your browser loads and arranges these tiles to display the area you want to see. This approach allows maps to be fast and responsive, loading only the tiles you need.

Maps use a coordinate system based on latitude and longitude to pinpoint locations on the earth. Latitude measures how far north or south a point is from the equator, while longitude measures how far east or west a point is from the prime meridian. These coordinates are usually expressed in decimal degrees, such as 37.7749, -122.4194 for San Francisco.

Web maps rely on a process called rendering to display map tiles in your browser. The map library calculates which tiles are needed for your chosen area and zoom level, then requests and displays them in a grid. As you pan or zoom, new tiles are loaded and old ones are removed, giving you a smooth interactive experience.

Another important concept is the map projection. The earth is a sphere, but computer screens are flat, so map projections are mathematical methods for translating the curved surface of the earth onto a flat plane. The most common projection for web maps is the Web Mercator projection, which preserves straight lines and shapes well enough for most mapping needs, though it does distort areas near the poles.

Zoom levels determine how much detail you see on the map. At a low zoom level, each tile covers a large geographic area and you see more of the world at once. As you increase the zoom level, each tile covers a smaller area, providing more detail. The combination of map tiles, projections, and zoom levels allows web maps to efficiently display vast amounts of geographic data in a way that is both accurate and user-friendly.