Classic Mode
Classic Mode is an option that can be selected upon creation of new worlds. On Old-gen console and , it is the only available option. As the name suggests, worlds in Classic Mode offer Terraria's "normal" gameplay experience which existed prior to the introduction of other world modes. As such, Classic Mode worlds do not feature the "creator" freedom of Journey Mode worlds, but nor are they as challenging as Expert Mode or Master Mode worlds.
While the world content of Classic Mode worlds in general mirrors that of the other worlds modes, it does not hold any Expert-exclusive or Master-exclusive items. There is no Classic Mode-exclusive content.
See the articles about Journey Mode, Expert Mode, and Master Mode for miscellaneous differences between Classic and other world modes, as Classic Mode is always used as a reference point.