Final answer:
An inode, or index node, is a control structure with metadata about a file, used by operating systems to efficiently manage files on Unix-based systems.
Step-by-step explanation:
An index node (inode) is a control structure that contains the key information needed by the operating system for a particular file.
This data structure is used in many Unix-based file systems and contains metadata about a file including the file's size, owner, permissions, as well as pointers to the disk blocks where the file's data is stored.
The indexing makes file access more efficient for the operating system as it does not have to read through the entire file system to find a file. Additionally, the inode number serves as a unique identifier for each file within the file system.
An attribute is a control structure that contains the key information needed by the operating system for a particular file. It provides the necessary metadata about the file, such as its name, size, location, and permissions.
An inode, or index node, is a control structure with metadata about a file, used by operating systems to efficiently manage files on Unix-based systems.