Dimensional lumber refers to wood that has been cut to standardized widths and depths, typically measured in inches. Common sizes include 2x4, 2x6, and 2x8, which indicate the nominal dimensions of the lumber. This type of lumber is widely used in construction for framing, flooring, and other structural applications due to its uniformity and strength. The term "dimensional" signifies that the lumber is processed to specific measurements, making it easier for builders and contractors to work with. It is usually made from softwoods like pine or fir, which are readily available and cost-effective for various building projects.