Before I purchase my first My Cloud, I would like to know if it is capable of copying (mirror image) the entire hard drive of my laptop - or is the My Cloud designed to just backup individual files? Thanks.
You can read through the User Manual for this information.
Visiting the WD web site you can compare all the My Cloud devices.
The My Cloud is a network attached storage device. It does not by itself backup anything on your computer. Rather you install software on your computer to perform a backup TO the My Cloud.
You can choose to use the Smartware backup software, the WD Sync program, or a third party backup program or sync program to copy or backup data from your computer to the My Cloud.
You can read the Smartware User Manual at the following link: http://www.wdc.com/wdproducts/library/UM/ENG/4779-705057.pdf