The Geocoding API allows you to find the coordinates (latitude/longitude) of a location based on the address provided. Additional features include reverse geocoding, batch geocoding, viewport biasing, thumbnail images, and more. Requests can be submitted as key-value pairs, JSON, and XML.
Almost every app that uses a mapping API needs latitude/longitude points. To get geocodes you need to convert an address to a point on the earth. That's where you'll need one of the 54 geocoding APIs in our directory. This post covers seven free geocoders and compares them on several aspects.