block and tackle
A rope and pulley system that helps lift heavy things.
A block and tackle is a system of ropes and wheels that makes lifting heavy objects much easier. The wheels, called pulleys, are mounted in frames called blocks, and a rope winds back and forth between them. When you pull on the rope, the pulleys work together to multiply your strength, letting you lift things that would otherwise be impossible to move.
Imagine trying to hoist a piano up to a second-floor window. One person pulling a rope tied directly to the piano wouldn't budge it. But with a block and tackle, that same person could lift it by pulling hand over hand on the rope. The trade-off is that you have to pull more rope: to lift the piano ten feet, you might need to pull fifty feet of rope through the system. You're not getting something for nothing. You're trading distance for force.
Sailors have used block and tackle systems for centuries to raise heavy sails and cargo. Construction workers use them on job sites. Rock climbers use similar pulley systems for rescue operations. The brilliant thing about a block and tackle is its simplicity: just wheels, rope, and the laws of physics, working together to turn human effort into serious lifting power.