Primitive civilizations used wood as material for building shelters, tools, weapons, utensils, and other items necessary for survival. As time went on, they began to expand the use of wood to include the creation of creature comforts such as furniture and decorative items. They also built boats and rafts for exploration, travel and trade. As skills and knowledge continued to develop, and woodworkers began to understand the wide variety of properties of woods from different tree sources, wood became one of the most widely used materials, found in nearly all areas of life, from home to work, production to pleasure. Those who had a talent for working wood became important artisans and craftsmen, and guilds and workshops were developed to help document and preserve the art, train apprentices, and represent the interests of those involved.