Also known as "coach bolt
From Wikipedia -
"Has a domed or countersunk head, and the shank is topped by a short square section under the head. The square section grips into the part being fixed (typically wood), preventing the bolt from turning when the nut
is tightened. A rib neck carriage bolt has several longitudinal ribs instead of the square section, to grip
into a metal part being fixed."
Can be used a torque washer
to reduce damage to the wood, and to facilitate easier installation and removal.