Teleportation: The ability to instantly transfer matter from one location to another without actually ever moving in the space between those two locations. Scientists have been chasing this dream for decades, and Science-Fiction writers and/or movie directors have been using it as a plot-device and/or a generic method of transportation for even longer.
In the context of MMORPGs, it is more and more often used as a way of letting players quickly “return to base” after having done some random quest in a far-off area of the game, instead of forcing them to spend what is seen as unnecessary time and effort fighting their way back the way they came. Usually it comes disguised as some sort of “fast-travel ability”, but whether it’s described as a map you use to find your way quickly (LotRO), as a special traveling ability using your knowledge of the “hidden paths between here and there” (AoC) or as magical spell that instantly transports you (World of Warcraft), the effect is exactly the same – you instantly teleport from one location in the game-world to another.
Another common feature comes in the form of fast-travel to specific parts of the game-world by the use of “space shuttles” (SWG), “wagoneers” (AoC) or just plain ol’ magic portals (UO, WoW).
In some games, you can also summon teammates to your location by magical spells, or to the entrance of a dungeon by the use of magical “meeting stones”, or open magical portals of your own which other players can step through to travel half way across the world. And as added in the most recent World of Warcraft-patch, the ability for members in a group to instantly teleport to the entrance of any specific dungeon, and when leaving said dungeon later on, being teleported directly back to one’s original location.
All of this is very handy, of course; it makes content instantly accessible to the players, makes it less of a hassle to team up with random players for a dungeon-rump, and ensures that you can meet up with your friends and guild-mates at short notice.