A series is a sequence of related events, objects, or elements that follow a specific order. In mathematics, a series often refers to the sum of the terms of a sequence, such as an arithmetic series where each term increases by a constant value. In literature and entertainment, a series can refer to a collection of related works, such as a book series or a TV series. Each installment typically builds on the previous ones, developing characters and plots over time, creating a cohesive narrative that engages the audience.