A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig bladder. Some balloons are used for decorative purposes, while others are used for practical purposes such as meteorology, medical treatment, military defense, or transportation. A balloon's properties, including its low density and low cost, have led to a wide range of applications. The inventor of the rubber balloon, (the most common balloon) was Michael Faraday in 1824, via experiments with various gases.
A toy balloon is a small balloon mostly used for child play, party decoration, and advertising.
Toy ballons are usually made of rubber or aluminized plastic, and inflated with air or helium. They come in a great variety of sizes and shapes, but are most commonly 10 to 30 centimetres in diameter.
Toy balloons are not considered to include "sky lanterns" (hot-air paper balloons), although these too are or were used as child toys in some parts of the world.