Summary  
This chapter introduces fundamental RDD actions that trigger computation: collect for retrieving elements into the driver’s memory, count for tallying the number of elements, and reduce for performing aggregations across partitions.

General domain of usage  
Distributed data processing

Learn the essentials of PySpark for big data analysis using real-world flights data. Explore Spark architecture, RDDs, DataFrames, and practical data processing techniques.

Core concepts and hands-on practice with PySpark using flights data.

RDD Actions: collect(), count(), reduce()