Board
A piece of lumber less than 2 inches in nominal thickness and at least 2 inches wide, the standard flat stock used for shelving, trim, fencing, and general woodworking.
In-Depth Explanation
In lumber industry terminology, a board is specifically defined as stock less than 2 inches in nominal thickness, distinguishing it from dimensional lumber (2 to 4 inches thick) and timbers (5 inches and greater). Common board sizes include 1x2, 1x4, 1x6, 1x8, 1x10, and 1x12 with actual thicknesses of 3/4 inch after surfacing. Boards are available in softwood species like pine and cedar and hardwood species like oak and maple. Softwood boards are graded for appearance with designations like Select and Common, while hardwood boards follow the NHLA grading system. Board footage is the standard unit for measuring and pricing hardwood boards.
Usage Example
I picked up six 1x6 pine boards at 8 feet long for the bookshelf project.