Lumber refers to wood that has been processed and prepared for use in construction or other projects. It is typically cut into standard sizes, such as 2x4s or 4x8s, and can be used for building structures, making furniture, or creating other items. The term "lumber" often refers specifically to sawn wood products, but it can also encompass wood that has been milled in other ways, such as by using a chainsaw or other cutting tool.