Below is a simplified, annotated version of what a modern CoolGUI teleport script looks like. Using this in online Roblox games violates Roblox's Terms of Service.
The term historically refers to an infamous, third-party exploit interface associated with legacy Roblox exploiting groups like Team c00lkidd. In Roblox, a "GUI" (Graphical User Interface) is simply a menu with buttons. A "universal teletransportation" script usually refers to a line of code executed via an external program to move a player to any coordinate or player in any game, regardless of the game's intentional design. ⚠️ The Dangers of Third-Party Exploits