Actions are operations in Spark; they help in working with the actual data set. They help in transferring data from executor to driver. In Spark, an action helps in bringing back data from an RDD to the local machine. They are RDD operations giving non-RDD values, which is unlike transformations operations, which only eject RDD as output. The reduce() function is an action that is implemented again and again until only one value is left. The take() action takes all the values from an RDD to the local node.
Check out this insightful video on Spark Tutorial for Beginners:
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