Apache Iceberg is an open-source table format designed for massive analytic datasets. It brings the reliability and performance of SQL tables to data lakes, enabling features like ACID transactions, schema evolution, and time travel. Essentially, Iceberg addresses the limitations of traditional data lake table formats by providing a more structured and efficient way to manage large-scale data. This allows for more reliable and faster data querying and processing across various data processing engines, such as Apache Spark, Trino, and Flink. In summary, Apache Iceberg greatly increases the ability for data engineers to effectively work with very large data sets.