What is a campaign?

What is a campaign (as the term is used in this role-playing calendar)?

A campaign, (or a game or a group), is a series of sessions, typically with the same group of players and the same group of characters, though often players (and especially characters) will come and go over the course of a campaign. A campaign will usually use only use one system, and when the system changes, even if the players and regular meeting time stay the same, you will have a new campaign.

Sessions that are part of the same game share information, such as typical location, game system used, GM, etc.