Billion is a term used to describe the number one thousand million, typically represented as 1,000,000,000. It is often used in financial contexts to represent a significant amount of money or to describe something that is extremely valuable. In terms of population, a billion typically refers to a very large number of people, such as one-seventh of the world's total population. Additionally, in the realm of technology, a billion can refer to the number of bytes in a gigabyte, which is a common measure of data storage capacity. Overall, billion is a term that conveys a sense of immense scale and significance.