Geocoding and Reverse Geocoding

Geocoding is the process of converting a text description of a location, most commonly a street address, into geographic coordinates; reverse geocoding performs the opposite conversion, turning a latitude and longitude pair back into a human-readable address. The most common geocoding technique, address interpolation, estimates a point along a street segment by using the known address ranges assigned to each end of that segment, so a request for "150 Main Street" is placed proportionally between the lowest and highest numbered addresses recorded for that block, rather than matching an exact surveyed building location — a method that is fast and requires relatively little data but can be noticeably inaccurate on long or irregularly numbered blocks.