A shed is typically a simple, single-storey structure in a back garden or on an allotment that is used for storage, hobbies, or as a workshop. Sheds vary considerably in the complexity of their construction and their size, from small open-sided tin-roofed structures to large wood-framed sheds with shingled roofs, windows, and electrical outlets. Sheds used on farms or in industry can be large structures. The main types of shed construction are metal sheathing over a metal frame, plastic sheathing and frame, all-wood construction, and vinyl-sided sheds built over a wooden frame. A culture of shed enthusiasts exists in several countries. In Australia and New Zealand there are magazines called The Shed, an association for shed enthusiasts (the Australian Mens Shed Association), and a book entitled Men and Sheds.