What is the method called that ensures the transfer of information from an application to a data storage system?

The method that ensures the transfer of information from an application to a storage system is usually called serialization. Serialization is the process of converting an object into a format suitable for storage or transmission (for example, to a file, database, or over a network). In Java, this could be serialization into a byte stream, JSON, XML, etc.

An example of serializing an object to JSON using the Gson library:

Gson gson = new Gson();
String json = gson.toJson(myObject);
// json can be saved to a file or database