A game series refers to a collection of video games that are related in terms of storyline, characters or gameplay. These games usually belong to the same franchise and may be developed by the same company or developer. The games within the series often share common themes, settings, and continuity with one another, making it easier for players to follow along as they progress through each installment. Some popular examples of game series include Mario, Final Fantasy, Call of Duty, Assassin's Creed, and Grand Theft Auto among many others.