• It is an open-source coordination service for distributed applications. Zookeeper is used to manage configurations in distributed systems.
• Leader node is responsible to manage the load across follower nodes.
• It is a service similar to DNS for nodes.
• Zookeeper is not a replacement for a Load Balancer.

References:

• Zookeeper use cases: https://zookeeper.apache.org/doc/r3.8.0/zookeeperUseCases.html
• Service discovery options: https://technologyconversations.com/2015/09/08/service-discovery-zookeeper-vs-etcd-vs-consul/