A look at real filesystems (the Unix way)

A filesystem includes both data and metadata
And directories obviously

Metadata is stored in the "inode" data structure
In each filesytem, inodes are numbered

A directory is just a list of names and inode numbers
Metadata is not directory-specific
Most users don't care about metadata

A directory is a "special" file, like devices and sockets
It doesn't feature an associated data area
The behaviour of open(), read() etc is different

For "normal" files, the inode describes the on-disk mapping
And any access is then routed to a storage device

Finally, the super-block offers summary information and stats