Transmission tower is a tall tower used to carry the high-voltage cable used in electric power transmission. The tower is high for a safe distance for people, animals or things below the high-voltage cable.
Most big towers are built as suspension towers. They only hold up the cables, not pull them. Tension towers pull on the cables. They work as terminal towers at the end of a transmission line, or on sharp turns, or as transposition towers. Most big towers are lattice structures. Smaller ones may be wood, concrete or steel poles.