Apache Parquet is an open-source columnar storage file format designed for efficient data processing and storage. It is optimized for use with big data processing frameworks like Apache Hadoop and Apache Spark. Parquet allows for better compression and encoding schemes, which helps reduce the amount of disk space used and improves query performance. The format is particularly well-suited for analytical workloads, as it enables faster data retrieval by reading only the necessary columns. This makes it a popular choice for data lakes and data warehouses, where large volumes of structured and semi-structured data are stored and analyzed.