What is a Kafka topic and how is it different from a traditional queue?

A Kafka topic is a named category to which producers write events. Unlike a traditional queue where each message is consumed by one consumer and then deleted, a Kafka topic is a persistent, ordered log. Multiple consumer groups can each read the entire topic independently and simultaneously. Messages are retained based on time or size, not consumption. This publish-subscribe with persistence model is fundamentally different from point-to-point queuing.

Expected key concepts: topic, named category, persistent log, multiple consumer groups, publish-subscribe, retention, ordered, point-to-point