A tongue and groove joint provide a mechanical means of joining the edges of narrow boards when forming a wider panel.

 

Beveled tongue and groove joint
Blind tongue and groove joint
Double dovetailed tongue and groove joint
Double tongue and groove joint
Dovetailed tongue and groove joint
Loose tongue and groove joint
Rounded tongue and groove joint
Secred nailing tongue and groove joint
Shiplap joint
Tongue and groove joint
Tongue and groove joint with bead
Tongue and staggered groove sides joint
Tongued grooved and veed joint