Description: DataFrame actions in Apache Spark are operations that trigger the execution of calculations on a DataFrame, which is a data structure similar to a table in a database. These actions are fundamental for data processing in Spark, as they allow users to obtain concrete results from stored data. Unlike transformations, which are operations that define a new DataFrame but do not immediately execute calculations, actions provoke the evaluation of previous transformations and the execution of necessary calculations. This means that when an action is performed, Spark must carry out all the work needed to produce the result, which may include reading data from storage, applying transformations, and writing results. Actions can include operations such as counting the number of rows, displaying data in the console, or saving the DataFrame in a specific format. The ability to differentiate between actions and transformations allows Spark to optimize data processing, using a DAG (Directed Acyclic Graph)-based execution model that improves efficiency and performance compared to many other data processing systems.
