Sheet piles are long, vertical sections of material, usually made of steel, concrete, or wood, that are driven into the ground to create a barrier. They are commonly used in construction and civil engineering to support excavations, retain soil, and prevent water infiltration. These piles interlock with each other, forming a continuous wall that can withstand lateral pressures from soil and water. Sheet piles are often employed in projects like docks, harbors, and retaining walls, providing stability and protection in various environments.