What does "scan mounted SD card" do?

ESET for android:

In the manual it says two things about this option:

* The On-access scanner checks files that you interact with in
real time. It automatically scans Download folder on the
SD card, files from the .apk installation files and files on
the SD card after it is mounted (if the Scan mounted
SD card option is enabled). The On-access scanner
launches automatically at system startup.

* Scan mounted SD card - scans the files prior to
opening or saving them to the SD card.

What I don't understand is:

1. Is this the option the controls the automatic scan of the complete external SD card after insertion and on phone startup?

2. If I disable this option, will files accessed in the SD card (external or internal) still be scanned?

Thanks.