Namenode

The NameNode is a central component in a Hadoop distributed file system, acting like a directory service for the entire system. It stores important metadata—such as the structure of files, where data blocks are stored across different machines, and permissions. When you access or modify files, the NameNode quickly provides the necessary information to locate and manage data stored on multiple DataNodes. Think of it as a master index or map that ensures data is stored efficiently and reliably, enabling smooth data retrieval and management across the entire network.