Google Geocoding Web Service is intended to enable precaching of geocoder results that you know your application will need in future. “For e.g., if your application displays property listings, you can geocode the address of each property, cache the results on your server, and serve these locations to your API application. This ensures that your application doesn’t need to geocode the address of a property every time it’s viewed by a user. However we do ask that you regularly refresh your cache of geocoder results. Also deprecated current service, now retroactively named the "Geocoding V2 Web Service". Existing applications using the V2 Web Service need not worry though. Deprecation indicates that we no longer intend to pursue any further feature development, but we will continue to maintain and support the service in accordance with the deprecation policy set out in the Maps API Terms of Service,” noted Google.
More info: Geocoding Web Service