Apache Kafka is a distributed computing system that enables multiple servers to work together for speed, durability, and scalability. It uses a cluster structure, where brokers manage load balancing, replication, and stream decoupling, and partitions are used to balance the workload across the cluster. Data is replicated across multiple servers to ensure stability and availability. Kafka balances load through load balancing and partitioning, allowing it to handle large volumes of data and provide low latency. The system uses a leader-follower model for replication, where followers replicate writes from the leader node to maintain data consistency. In case of failure, KRaft, a metadata management system, is used to manage the cluster's metadata and trigger leader elections. Kafka can be run on-premise or in the cloud, providing developers with flexibility in choosing their deployment option. The system also uses events as a fundamental concept, enabling event-driven design, event sourcing, designing events, and event streaming.