Finger Joint

A series of fingers machined into the ends of two pieces of lumber to be joined together. They are then held firmly in position by adhesive. Finger jointed wood is very strong and has a lesser chance of warping than does a clear piece of wood the same length.

Finger_joint (Wikipedia)
A number of different finger joint profiles used decoratively.

A finger joint, also known as a comb joint, is a woodworking joint made by cutting a set of complementary, interlocking profiles in two pieces of wood, which are then glued. The cross-section of the joint resembles the interlocking of fingers between two hands, hence the name "finger joint". The sides of each profile increases the surface area for gluing, resulting in a strong bond, stronger than a butt joint but not very visually appealing. Finger joints are regularly confused with box joints, which are used for corners of boxes or box-like constructions.