Bungee is a strong, stretchy cord made from many rubber strands woven together, designed to snap back after being pulled. You've probably seen small bungee cords with hooks on each end used to strap luggage to a car roof or hold a bike in place. When you pull on a bungee cord, it stretches out like a giant rubber band, then bounces back to its original length when you let go.

The most dramatic use of bungee cords is in bungee jumping, an extreme sport where people jump from bridges or platforms with a bungee cord attached to their ankles. The cord stretches as they fall, then bounces them back up, creating a thrilling yo-yo effect hundreds of feet in the air. The first modern bungee jump happened in 1979, when members of the Oxford University Dangerous Sports Club jumped from a bridge in Bristol, England.

Today, bungee cords are practical tools found in garages and storage rooms everywhere. They're useful because they hold things tightly while still allowing some give and flexibility, unlike rope or string.