The inode ( also known as Index Node) is a very basic concept related to Linux and UNIX filesystem. Each and every object/element in the filesystem is associated with an inode.
You must be aware of the fact that, most of the countries have given a unique identity to their citizens in the form of a unique identification number ('Aadhar Card' in India and 'SSN' in the USA) to identify an individual easily and uniquely. This also leads to make all the paper work corresponding to any citizen easier to be handled.
Just like these identification numbers for people, there is a unique identity of every member of a Linux filesystem which is known as Inode number and it uniquely exists for each and every individual file on Linux or Unix filesystems.
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