I'm using Apache Kafka 0.8.2.1, planning to upgrade my application to use Apache kafka 1.0.0.
While I inspect about Kafka Streams, I got some question about difference between KafkaConsumer and KafkaStreams.

Basically, KafkaConsumer have to consume from broker using polling method. I can specify some duration while polling, and whenever I got ConsumerRecored I can handle it to product some useful information.
KafkaStream, on the other hand, I don't have to specify any polling duration but just call start() method. 

I know that KafkaConsumer basically used to `consume` literally, from broker and KafkaStreams can do various thing like `Map-Reduce` or interact with database, even re-produce to other kafka or any other systems.

So, there is my question. Is there any difference between KafkaConsumer and KafkaStream basically(in other words, When it comes to level of apache kafka library.)?