A teleport move is a move intended strictly to move from one place to another. It does not have an attack hitbox; if it does, it is generally classified as a rushing move or a moving throw.
Most teleport moves either warp (with the character’s body disappearing wholly or partially during transit), run (sort of like a dash), or tumble (like a roll).
Also, most teleport moves don’t have a touch hitbox, so they will go right through the opponent; some do, and will either stop at the opponent, or push them somewhat.
Most teleport moves are intended to go forward, but some can go backwards and upwards. Those few that can be used in midair tend to go diagonally or straight downward.
Because teleport moves only move, they are almost never found as super special moves, and rarely use the meter.
Many teleports have some sort of invincibility, but even so, they are usually open during the outset and at the very end.
Many of them are special moves, so they often can be cancelled from normal moves, useful for throwing things out of order and evading flailing.
The teleports that do not have invincibility often allow one to use an add-on move to attack, and in these cases, they are primarily useful for the attack.