Definition: Additional-Namesnodes-Spark-defaults-conf: Configuration file for Spark application, specifying additional configuration settings for the Spark environment. Additional means added to a system or process. In this case, it's adding an additional node to Spark that's capable of handling additional workloads beyond what was initially planned. This might be used in situations where the original application had too many small, unrelated tasks running concurrently and they need more resources (such as memory or CPU).