title: KafkaProducer: Difference between `callback` and returned `Future`?
body: <p>The <a href="https://kafka.apache.org/0100/javadoc/index.html?org/apache/kafka/clients/producer/KafkaProducer.html" rel="noreferrer">KafkaProducer send method</a> both returns a Future and accepts a Callback.</p>
  
  <p>Is there any fundamental difference between using one mechanism over the other to execute an action upon completion of the sending?</p>