Hierarchical File System (HFS) is a new filesystem that was developed by Apple in 1996. All Apple mobile devices use HFSX as the filesystem. The HSFX filesystem is a variation of the HFS plus filesystem. The major difference between HFS plus and HFSX filesystem is that HFSX is case sensitive:

On the other side, HSF plus is not case sensitive as shown in the following:

There are basically two ways to acquire forensics data from iPhone devices, as shown in the following:
Physical acquisition (live forensics)
Data backup acquisition
We will study the overview of both techniques.