The transporter pad (or transporter platform) is a vital component of the transporter system, where in which an object or individual stands so that they can be transported to the desired location.
Aboard Federation starships a standard transporter contains six transporter pads for personnel transport and one for the transport of objects, though the center pad can also be used for personnel in emergencies. A cargo transporter contains one large transporter pad and is used primarily for the transport of goods, though they can also be used for moving large numbers of personnel in an emergency.
In the 24th century, Starfleet transporter pads contained four redundant molecular imaging scanners, so if one scanner should fail one of the three backups could kick in. As a security measure, a transporter pad can also have a force field projected around it, although this has also been seen in use with other transporter systems, such as the pad located in the operations center of Deep Space 9. (TNG episode: "Realm of Fear" and DS9 comic: Lapse).
In an alternate timeline where Montgomery Scott rescued James T. Kirk before he could be absorbed into the Nexus, Alliance vessels were equipped with an Interrogation chamber; the only access to this section of the vessel was via a single transporter pad inside a cubicle. (Star Trek novel: Engines of Destiny)