By default, Kafka brokers use the PLAINTEXT protocol for network communication. This means:
* No encryption - data is sent in plain text.
* No authentication - any client can connect without verifying identity.
* No authorization - there are no access control checks by default.
Security features like TLS, SASL, and ACLs must be explicitly configured.

The recommended and safe method to delete a topic is to use the Kafka CLI tool kafka-topics.sh --delete command, provided that delete.topic.enable=true is set on the brokers.

Partitions are the primary mechanism for achieving load balancing in Kafka. When a topic has multiple partitions, Kafka clients (producers and consumers) can distribute the load across brokers hosting these partitions.

Kafka ACLs (Access Control Lists) perform authorization checks every time a client attempts to access a resource (e.g., topic, consumer group). This ensures continuous enforcement of permissions, not just at connection time or intervals. This approach provides fine-grained security, preventing unauthorized actions at any time during a session.

Kafka Streams is a client library for building real-time applications that process and analyze data stored in Kafka.
ksqlDB enables event stream processing using SQL-like queries, allowing real-time transformation and analysis of Kafka topics.