A truss is a structure composed of slender members connected at their ends to form a rigid framework. It is commonly used in bridge and roof construction, and its purpose is to support loads applied along its length. Trusses are typically constructed from steel or aluminum, but can also be made from wood or other materials. The most common type of truss is the triangular truss, which consists of three members connected at their ends to form an equilateral triangle. This type of truss is very efficient in resisting both bending and tension forces, making it ideal for structures that require large spans with minimal material usage.