What are topics and partitions in Kafka?

In Apache Kafka, a topic is a logical category or channel where messages are published. A topic can be thought of as a stream of data divided into different subjects.

Partitions are physical segments within a topic. Each topic is divided into multiple partitions for scalability and parallel processing. Messages within a partition are ordered and have a unique offset index.

Partitions allow:

• Parallel reading and writing of messages
• Fault tolerance (partition replication)
• Guarantee of message order within a partition

Example: The "orders" topic can have 3 partitions, and order messages will be distributed among them.