We don't have a clue about how to really build a device like the transporter. Or it captures a person's pattern, dematerializing him or her, and brings the person to some other point. All of the rematerialized atoms and mol ecules are somehow in the precisely correct positions, with the right temperatures and adhering together just as if the transportee had not been dematerialized. Nothing in the physics of today gives a hint about how that might be possible. But we can't assume every magical feat could be accomplished, given sufficiently advanced technology.
Holograms are apparent images with three dimensional structure.
We can't imagine a way to assemble matter in the same way as the light in a hologram. As this is used on the Star Trek shows, it's just an automagical device to enable characters to get through the stories. It would be too tedious and repetitious in a one-hour show for the characters to overcome real language barriers in a realistic manner in every show. We can certainl dismiss the possibility of such an invention ever being built. Despite its fundamental role in the show's plot, it violates known physics to an extent that can't be defended.