These pipes appear to blanket the land in the Mushroom Kingdom and its surrounding territories. Though the world of Mario may be filled with other kinds of transportation, this is clearly Transportation for the masses. Allowing its user to travel to all kinds of new and exotic lands.
The name Warp Pipe was coined in the first Mario game. In level 1-2 after running along the top of the stage a room called Warp Zone can be found, which has 3 pipes in it that lead to stages later in the game. Since then, they have been refereed to as Warp Pipes.
These Pipes have appeared in the majority of Mario games. One notable exception is the American version of Super Mario Bros 2. Players can travel using large pots, but the Warp Pipe itself does not make an appearance.