Understanding marker clustering
The clustering technique divides the map into squares of a certain size (the size changes at each zoom level), and groups the markers into each square grid. It creates a cluster at a particular marker, and adds markers that are in its bounds to the cluster. It repeats this process until all markers are allocated to the closest grid-based marker clusters based on the map’s zoom level. If markers are in the bounds of more than one existing cluster, the map determines the marker’s distance from each cluster, and adds it to the closest cluster.
Clustering simplifies your data visualization by consolidating data that are nearby each other on the map in an aggregate form. Activating this option when having a large number of markers on a map will significantly increase the loading speed of the map!