Gazillion is not an official number in the mathematical sense; rather, it is a colloquial term used to convey an extremely large, indefinite quantity. People often use it to express something vague or to emphasize the vastness of a figure, especially in informal settings.
For example, you might hear someone say, “There are a gazillion stars in the sky,” meaning there are far too many to count. In essence, while you won’t find ‘gazillion’ in a math textbook, it effectively communicates the idea of something being very large or innumerable.