A wormhole is a connection between two widely-separated points in space-time used for traveling throughout the universe. So far, only the Voltron Lions and the Castle of Lions have been shown to clearly utilize wormholes for travel. The Castleship uses teludav technology, while the Lions' exact methods have yet to be explained.
Wormholes appear as circular and intricate designs of light for their entry points. Inside, they are an intense and wild tunnel of energy. They can be used to travel a far as galaxies away from a point in space-time. Exiting the wormhole can be accomplished through the "sides" of the tunnel, and those who exit in separate spacecrafts can either end up in the same location or elsewhere in space-time.
When corrupted by Haggar's magic, it has been shown that a void, complete nothingness, can appear within the wormhole, and colliding with this void causes repetition of time within the wormhole with alterations to reality, such as the Altean Mice becoming different creatures and Coran de-aging each collision. Within such a wormhole time-loop, Allura is shown able to experience repeated flow of time and recall the events of the previous time flow; Coran, notably, does not appear to share this ability. Exiting a corrupted wormhole has only been accomplished after connecting with an external signal, such as from the Green Lion.
Teludav devices are used for creating wormholes and are built from the scaultrite material produced by Weblums. The Teludav is typically a large room full of scaultrite lens stones that create a magnifying beam generator; this uses a Crystal to convert Altean energy into usable fuel to power the device, such as from Allura as she is piloting the Castle of Lions. The magnified beam is so powerful it can be fatal to come in contact with. It is possible to create a wormhole with this technology from the residual energy stored in the teludav. If the teludav is over-used, the lenses begin shattering, throwing a spacecraft out of a wormhole unplanned and preventing any wormholes from being created.
Teludavs can also take the form of a megastructural ring, as seen as the teludav used to transport Zarkon's command ship. Powering a teludav of such massive size can be threatening to an Altean's life. Only a few Alteans were capable of utilizing teludav technology in the past; the only living Altean known with this ability is Allura.