In Star Trek the premise was they were using photons and force fields to create the illusion of real objects. Since your eyes work by registering photons to start with, that made sense. But as far as I will speculate, the force fields were used to give the image a solid feel. Our current tech is no where near that.
If you saw the first Iron Man movie, when he returned to his lab and got the suit project going, he had a hologram he could put his arm in to and it moved with him. We have that tech now but it takes a special set up to display the hologram and a sophisticated camera and computer to track the movement.
Maybe one day we'll have a holodeck of sorts, but not in this century.