WDC_SAM driver

I recently purchased two “WD easystore 14TB External USB 3.0 Hard Drives”. I attached them to my PC and let Windows do its thing to install drivers etc. and they show up as “WD easystore 264D USB Device” in Device Manager. Note, I did NOT manually install any software, e.g. the “Install Western Digital Software for Windows.exe” that was found on the drive.

However, I noticed Windows Update now reports a new optional driver update - a “Western Digital Technologies - WDC_SAM - 11/30/2017 12:00:00 AM -” is listed as an optional driver update.
What is this WDC_SAM driver? What kind of functionality does it provide and will be missing by not installing it?
Why wasn’t it installed when the drivers for “WD easystore 14TB” drives were installed?