Unlike traditional message queues that delete messages after consumption, Apache Kafka is a distributed, append-only commit log . Events are persisted to disk and can be replayed at any time.

Here is a quick breakdown of how it works.

1. Core Primitives

Topic: A logical stream of events (e.g., orders ).

Partition: Slices of a topic spread across brokers to enable horizontal scaling.

Offset: A sequential, immutable ID ( 0, 1, 2... ) assigned to every record in a partition.

Broker: A Kafka server node that stores partitions and serves client requests.

2.…