Analysis of information sources in references of the Wikipedia article "File system" in English language version.
The word dentry is short for 'directory entry'. A dentry is nothing but a specific component in the path from the root. They (directory name or file name) provide for accessing files or directories[.]
HDD still key storage for the foreseeable future, SSDs not cost effective for capacity
APFS introduces space sharing between volumes. In APFS, every physical disk is a container that can have multiple volumes inside, which share the same pool of free space.
Pooled storage: adding physical storage devices to a pool, and allocating storage space from that shared pool. Space is available to all file systems and volumes, and increases by adding new storage devices to the pool.
A filesystem is the methods and data structures that an operating system uses to keep track of files on a disk or partition; that is, the way the files are organized on the disk.
