A bubble is a thin sphere of liquid, typically formed from a mixture of soap and water. When air is trapped inside this liquid film, it creates a bubble. The surface tension of the liquid helps maintain the bubble's shape, allowing it to float and shimmer in the light. Bubbles can vary in size and are often seen in everyday life, such as in bubble baths or when blowing bubbles with a bubble wand. They are also used in scientific experiments to study properties of liquids and gases, showcasing the fascinating interactions between different materials.