A truss is a structural framework made up of triangular units that work together to support loads. It is commonly used in bridges, roofs, and towers due to its ability to distribute weight evenly and provide stability. The triangular shape is key, as it prevents deformation and allows the structure to withstand various forces. Trusses can be constructed from materials like wood, steel, or aluminum, depending on the application. They come in various designs, such as the Warren truss or Pratt truss, each suited for different engineering needs. Overall, trusses are essential in modern construction for their strength and efficiency.