What do you mean by geocoding api free?

Geocoding is the process of converting addresses (like "1600 Amphitheatre Parkway, Mountain View, CA") into geographic coordinates (like latitude 37.423021 and longitude -122.083739), which you can use to place markers on a map, or position the map.
The Google Geocoding API calculates latitude and longitude coordinates from addresses. The Google Maps Geocoding API provides a simple interface for converting addresses to locations and back.

Geocoding API is used to convert a street address into geographic coordinates (latitude and longitude), the process of converting addresses (like yours or mine) into locations on the Earth's surface. Using JavaScript, developers can access Google Maps APIs, enabling them to embed interactive maps into their sites and applications.

A geocoder converts a street address (like "1600 Amphitheatre Parkway, Mountain View, CA") into geographical coordinates (like latitude 37.423021 and longitude -122.083739). A geocoder tells you where in the world that address is. Geocoding is different from reverse geocoding, which converts geographical coordinates into a human-readable address.