A raft is a flat floating platform, often made by tying logs, planks, or barrels together. Unlike boats with curved hulls, rafts sit directly on the water's surface. You might build a simple raft from wooden pallets and empty plastic jugs, or ride a commercial whitewater raft down a rushing river.

Throughout history, people have used rafts to cross rivers, transport goods, and escape danger. In The Adventures of Huckleberry Finn, Huck and Jim drift down the Mississippi River on a log raft, using the current to carry them along. Sailors on sinking ships climb onto life rafts, inflatable platforms designed to keep them afloat until rescue arrives.

The word also means a large number or amount of something. A teacher might assign a raft of homework before winter break, meaning a whole lot of it. If your friend complains about a raft of chores, they're facing a big pile of tasks.

Rafts work because they spread weight across a large surface area. Even though each log might barely float on its own, together they create enough buoyancy to support people and cargo. That's why rafts have been so useful: you can build one from whatever materials you have available, with no advanced carpentry required.