I recently started learning Kafka and end up with these questions.

1. What is the difference between Consumer and Stream? For me, if any tool/application consume messages from Kafka is a consumer in the Kafka world.

2. How Stream is different as this also consumes from or produce messages to Kafka? and why is it needed as we can write our own consumer application using Consumer API and process them as needed or send them to Spark from the consumer application?

I did Google on this, but did not get any good answers for this. Sorry if this question is too trivial.