A pacifier is a small rubber or silicone nipple that babies suck on to comfort themselves. Babies have a natural instinct to suck, even when they're not hungry, because the sucking motion calms them down and helps them feel safe. A pacifier satisfies this need without feeding them.

Parents often give pacifiers to fussy babies to help them settle down or fall asleep. The pacifier has a nipple part that goes in the baby's mouth, a round shield that rests against the lips, and a handle so parents can grab it easily. Some babies love their pacifiers and get very attached to them, while others reject them completely.

Pacifiers go by different names in different places. In Britain, people call them dummies. Some American families call them binkies or soothies. Whatever you call them, they serve the same purpose: helping babies feel calm and content.