Spark is a fast and general engine for large-scale data processing. It provides APIs for Java, Scala, and Python that allow users to load data into a distributed cluster as resilient distributed datasets (RDDs) and then perform operations like map, filter, reduce, join and save. The Cassandra Spark driver allows accessing Cassandra tables as RDDs to perform analytics and run Spark SQL queries across Cassandra data. It provides server-side data selection and mapping of rows to Scala case classes or other objects.