- The talent, who perform on a set (either real or virtual via greenscreen) in a sound studio;
- The studio crew, including one or more camera operators and a floor director to relay signals from the control room to the talent;
- And the control room crew, including the director, who quarterbacks the whole thing, and people to manage the sound and video mixers and the recording equipment. The interesting thing is that in many (though not all) studio setups, the control room crew cannot necessarily see or hear everything going on in the studio — everything is done entirely from the camera's POV.
I Love Lucy and Desilu Studios, and used extensively in other settings, especially news and talk shows. On the whole it doesn't look a whole lot like a stereotypical movie production — the director is off-set behind a wall of video screens, connected to the stage floor primarily by a rat's nest of wires, a wall of video screens and mixing equipment, and various forms of intercoms. The show is shot with three simultaneous cameras, often before a live audience. This greatly reduces the number of times a scene needs to be reshot for technical reasons (now we do the same scene for closeups, now we do the same scene with two-shots), as well as making editing easier by greatly reducing continuity issues (especially if the actors tend to drift off the script). The three-camera system and extensions thereof (sporting events can have dozens of cameras) is pretty standard in many live or live-to-tape television shows. Readers with access to a local public-access cable channel can usually learn the details quite cheaply, but essentially the system works as follows: