Kafa Streams

Hi,

I'm looking over your documentation at docs.confluent.io on Kafka Streams,
but I couldn't find the information I'm looking for. What I need to know
are:

1. When should one use Kafka Stream instead of regular Kafka Consumer?
2. If I'm not performing data transformation, but simply reading from Kafka
and saving the data to a DB, should I use Kafka Stream? What advantages do
I have over Kafka Consumer?
3. How does Kafka Stream provide fault tolerance over regular Kafka
Consumer?

Please advise. Thanks.

Samson