With old-growth forests virtually gone, the days of finding 2-foot wide planks of wood are long gone, and today's woodworker needs to make do with much smaller pieces, all glued together to form one wide board. One can rest assured that the glued joint is often as strong as the wood to which it is attached, and with some creative joint techniques, the joint can even be made stronger.
Edge joints deal with the joining of long grain with long grain, and this is a very stable situation since any movement in the wood due to moisture expansion will be across the grain. The joint between long grain will allow both pieces to move in tandem with each other, thereby preserving the integrity of the joint.
The following joints are classified as edge joints: