A topsail ("tops'l") is a sail set above another sail; on square-rigged vessels further sails may be set above topsails.
USS Constitution sailing under (bow to stern) jibs, topsails, and spanker.
La Recouvrance with both a gaff topsail and two square topsails; the partly obscured sail between the topmasts is a topmast staysail
Image: Sails 19th century ship
A full-rigged ship or fully rigged ship is a sailing vessel with a sail plan of three or more masts, all of them square-rigged. Such a vessel is said to have a ship rig or be ship-rigged, with each mast stepped in three segments: lower, top, and topgallant.
Full-rigged sailing ship Christian Radich
Full-rigged sailing ship Royal Clipper
Amerigo Vespucci, full-rigged ship of the Italian Marina Militare
HMS Lutine, a French-built ship-rigged frigate of the late 18th century