Wood signs or wooden signs can be made from a variety of materials and use various techniques.  The terms for custom wood signs often gets used interchangeably and can include:  MDO board signs, sandblasted signs, redwood signs, cedar carved sign, painted sign, neighborhood entrance sign, and many other references.
MDO board is a type of plywood often used in custom wood signage.  Sandblasted signs are usually made from cedar or redwood.   Nearly any type of wood can be used to make a wooden sign using either a carving, engraving, blasting, painting, or finishing technique.
The term “wood sign” or “wooden sign” in the context of business signage, typically refers to a sandblasted sign.