A "Series" is a collection of related items or events that follow a specific order or pattern. In literature, a series can refer to a set of books featuring the same characters or themes, like the Harry Potter series. In television, a series consists of episodes that tell a continuous story, such as Friends or Game of Thrones. In mathematics, a series is the sum of the terms of a sequence. For example, the series of numbers 1, 2, 3, and so on can be added together to find their total. Understanding series helps in various fields, including science, finance, and art.