What are the action operations and transformation operations in Spark?

Actions in Spark refer to operations that perform calculations on RDD datasets and return results, such as collect, count, reduce, etc. These operations trigger Spark’s computing tasks and return the results to the driver program. Transformations, on the other hand, refer to operations that transform RDD datasets and return new RDD datasets, such as map, filter, flatMap, etc. These operations do not trigger computing tasks immediately; only when encountering action operations do they trigger actual computing tasks. Actions and transformations are two very important types of operations in Spark that can be used for data processing, analysis, and computation.