The showrunner is the producer who commands a show's day-to-day operations. The showrunner, who is sometimes the very person who comes up with the initial show concept, hires and supervises the show staff, decides what is included in each show, makes sure the show stays within budget, and works in conjunction with other producers, staff members, technical crew members, and post-production personnel to watch over a production's overall activities. Showrunner responsibilities differ from those of an executive producer who, though still responsible for the overall production, typically handles the show's business and legal issues.
Several other producers with titles like "co-producer" perform other hands-on functions under the showrunner's guidance. A writer, or team of writers, drafts the show's script, which the director will study in order to map out how he wants to shoot. The wardrobe department works to properly outfit the actors; and the production designer and property master work on designing the set and securing all needed props, respectively. Production assistants, or PAs, typically do the foot work. A PA may be assigned to help set up a scene one day and the next could running errands.
The preproduction phase is intended to get everything in order before the camera's roll. The basic ideas and approach for the show are formulated and first put into motion through a series of these meetings long before anything airs. The talent and production team members are selected during this time. Set designers, cameramen and other technical personnel are hired as well. For shows already in progress, a common preproduction element is the table read. The actors and the director will just sit together and each performer will read her part out loud. The showrunner and director will use this time to work out problems if certain lines don't sound right. The script will usually go through a endless stream of notes and rewrites before it is actually approved to shoot.
The production phase is where the script is actually shot. Depending on the kind of show it is, shooting on a single script may last a handful of hours or a several days. Only essential personnel are usually on a set during the actual taping or filming of a TV show. Some programs trying to keep its dramatic elements secret _ like former hits "The Sopranos" and "Lost" _ make a great effort to keep unauthorized people away during shooting, especially if the show is shot on location.
After taping is completed, the footage goes to editors who, normally in consultation with the director, piece it together to tell the full story the director and showrunner(s) want. Editors usually work under tight deadlines, depending on how soon the show will air after taping. Post-production may also involve adding music and effects to the show, or having actors do new readings to replace dialogue on the tape that the director no longer likes. If the editor does his job correctly, the viewer should not be able to tell any such changes were made.