Atlas Stream Processing is a native stream processing solution integrated into MongoDB Atlas that offers an easy developer experience, cost savings, and performance advantages when using Apache Kafka in applications. It extends the MongoDB Query API to enable continuous data processing and supports advanced use cases not possible with the Kafka Connector. The decision between Atlas Stream Processing and the Kafka Connector depends on factors such as ease of use, performance, and cost. Atlas Stream Processing is a fully managed service that charges per Stream Processing Instance worker, offering potential cost savings compared to the Kafka Connector's task-based pricing model.