What is a coaster brake on a bicycle and how does it function in comparison to other types of brakes?

A coaster brake on a bicycle is a type of brake that is activated by pedaling backward. When you pedal backward, the brake engages, causing the bike to slow down or stop. This type of brake is different from other types of brakes, such as hand brakes, which are activated by squeezing levers on the handlebars. Coaster brakes are often found on cruiser bikes and are known for their simplicity and ease of use.