Apache ORC is a highly optimized columnar storage format used primarily with Hadoop ecosystems for managing large-scale data. It is designed to provide efficient compression and high-performance query capabilities. ORC organizes data by columns rather than rows, which significantly improves read performance for queries that access only a subset of columns. It supports advanced compression techniques and features like lightweight indexes to boost query speed and reduce storage costs. ORC is particularly useful for analytics and big data applications where performance and storage efficiency are crucial, making it a popular choice for data warehouses and analytical processing systems.