What is a Kafka broker's bootstrap.servers configuration?

bootstrap.servers is a comma-separated list of host:port pairs that a Kafka client uses for initial cluster discovery. The client connects to at least one listed broker to fetch cluster metadata (all brokers, topic-partition-leader assignments). After getting the metadata, the client routes requests directly to appropriate brokers. You don't need to list all brokers — typically 3 is sufficient for resilience. Example: bootstrap.servers=broker1:9092,broker2:9092,broker3:9092

Expected key concepts: bootstrap.servers, comma-separated, initial discovery, cluster metadata, all brokers, topic-partition, leader, 3 brokers, resilience