This document compares Apache Spark and Apache Flink. Both are open-source platforms for distributed data processing. Spark was created in 2009 at UC Berkeley and donated to the Apache Foundation in 2013. It uses resilient distributed datasets (RDDs) and lazy evaluation. Flink was started in 2010 as a collaboration between universities in Germany and became an Apache project in 2014. It uses cyclic data flows and supports both batch and stream processing. While Spark is currently more mature with more components and community support, Flink claims to be faster for stream and batch processing. Overall, both platforms continue to evolve and improve.