What is Blocking mode in Samsung Galaxy Note3(SM-N900)?

The Blocking mode lets you disable incoming calls (except for those on the allowed list), notifications, alarms, and the LED indicator. In your Samsung mobile place a check mark next to the features you would like to disable. When the feature is on, a green check mark will appear. Choose from Block incoming calls, Turn off notifications, Turn off alarm and timer, and Turn off LED indicator.

( Blocking Mode )

 
Set the time you would like the Blocking mode to be active for, or select Always to keep it on constantly. To receive notifications, select Allowed contacts and then select Custom to add specific contacts to the "allowed contacts" list.