In Star Trek, what is the device used to teleport people called?

In Star Trek, the device used to teleport people is called a transporter.

A transporter converts a person or object into an energy pattern, sends that pattern to a destination, and reconstructs the matter through a process called rematerialization. Characters commonly refer to using it as “beaming,” and the operator traditionally gives the command “Energize.”

The transporter first appeared in Star Trek: The Original Series, whose production used the concept partly to avoid showing expensive starship landings. It soon became one of the franchise's defining technologies. Transporter rooms usually contain a platform, control console, pattern buffer, and related scanning equipment.

The transporter is not the same as a shuttlecraft, which physically travels through space. Nor is it a replicator, which creates objects from stored patterns, or a holodeck, which produces immersive simulations. Transporter malfunctions are also a recurring plot device, sometimes splitting, merging, or otherwise altering characters.