Carpenters' grooves are a type of joinery used in woodworking. They are created by cutting a groove into the edge of two pieces of wood, which are then joined together. The two most common types of carpenters' grooves are dados (5 letters) and dadoes (6 letters). Dados are shallow grooves cut across the grain of the wood, while dadoes are deeper grooves cut along the grain of the wood. Both types of grooves provide a strong joint between two pieces of wood, making them an essential part of carpentry.