Infinity is a concept that describes something without any limit or end. In mathematics, it often represents an unbounded quantity, such as the endless numbers that continue beyond any given point. It is symbolized by the figure eight turned sideways (∞) and is used in various fields, including calculus and set theory. In philosophy and science, infinity can refer to the idea of endlessness in time, space, or quantity. For example, the universe may be considered infinite if it has no boundaries. Additionally, concepts like infinite series in mathematics explore how sums can approach infinity, revealing deeper insights into numerical behavior.