A Parquet file is a columnar storage file format used in the Big Data ecosystem, designed for efficient data storage and processing. It organizes data into columns rather than rows, allowing for better compression and faster query performance.

Advantages of Parquet files include:

1. Efficient Compression: Parquet uses advanced compression techniques, reducing storage space and improving read performance.
2. Columnar Storage: Data is stored in columns, enabling selective columnar reads and minimizing I/O operations.
3. Schema Evolution: Supports schema evolution, making it easier to add or modify data fields without affecting existing data.
4. Compatibility: Widely supported in Big Data frameworks like Apache Spark, Hive, and Impala.
5. Performance: Parquet files enhance query performance due to their optimized storage layout.