The spark-redis package provides a Redis connector for Apache Spark, allowing users to access and manipulate Redis data structures as RDDs. To test its capabilities, the author set up a standalone Apache Spark cluster and used it to count words in Redis's source code files. The results were then stored in a Sorted Set for later querying. The author also demonstrated how to store word counts for each file in its own Sorted Set and reduce them to a single total using the spark-redis connector. Additionally, the package provides cluster-aware data access and reduces inter-engine shuffling, making it a powerful tool for big data processing.