The Auto Sensing advantages are as below.

Reduce barcode input mistake in Continuous mode.
Traditional Continuous mode applies scanning beam continuously. The continuous scanning beam could mistakenly capture barcode input which is actually not a barcode data. Such mistake happens because of environmental unstable light strength which is similar as a barcode data being detected.

Power saving
In traditional Continuous mode, the continuous scanning beam keeps consuming power. Auto Sensing allows the  scanning beam to be off. The scanning beam will be turned on when an object (a barcode) is detected, and will turn off again when no object (no barcode) is detected.

Makes barcode scanner more durable when using Continuous mode.
Because the scanning beam is not always on, therefore the scanner becomes more durable.
Note: Auto Sensing requires a stand, and both the barcode scanner and the stand must support Auto Sensing.