Files

A file is an array of bytes associated with an inode.

inodes

Inodes contain information on file type, owner, permissions, timestamps, # of hardlinks, # of blocks, and pointer to data blocks.

file descriptors (fd)

A fd is an index in the open file table that points to an entry in the inode table

To the program, a fd the means in which you interact with an open file.

Hard Links vs Soft Links

Hard links creates a file pointing the same inode of the linked file while soft links only points to the file name.