Google Maps for those who don't know is a mapping service developed by Google. It offers satellite imagery, street maps, 360-degree panoramic views of streets, real-time traffic conditions, and route planning when traveling.
In this situation I am using google maps API to show buildings on google maps as per their locations. A Marker is used to plot buildings on google maps. But, when two or more markers are very close to each only then a single marker is displayed on google maps which makes it difficult to identify the number of available markers at the same point. To address this problem, there are two techniques for Markers, Spiderfier and Clustering.