Partitioning a hard drive is useful to organize data.
At the very least it can help you separating your personal files from the system files.
Creating partitions is a basic functionality that every partition management software has.

Clone Partition
Everyone knows the importance of having a good backup.
One of the existing methods to backup files is to backup the partition where the files are stored.
Those files are still retained in the hard drive and thus recoverable with the aid of a recovery tool.

It is for this reason that any file that you deem as important must be securely deleted.
As an alternative, you might also wipe the entire content of your hard drive with AOMEI Partition Assistant.
Hide Partitions
Privacy may become a concern when you share a computer with another person.
The partition will be unusable when it is hidden.
To regain access, it has to be unhidden.
Note that when you unhide the partition, its drive letter may change to a new one.
Still, it wont cost you anything but some small space in the disk to keep it at hand.