The Hadoop Distributed File System (HDFS) is a key component of the Hadoop framework, designed to store large volumes of data across multiple machines. It breaks down files into smaller blocks, typically 128 MB or 256 MB, and distributes these blocks across a cluster of computers. This distribution allows for efficient data processing and fault tolerance, as data is replicated across different nodes. HDFS is optimized for high-throughput access to large datasets, making it suitable for big data applications. It operates on a master-slave architecture, where a single NameNode manages the metadata and multiple DataNodes store the actual data blocks. This structure ensures scalability and reliability in data storage.