Write the Show
The first step in making a television show is to write the script. If it is a brand new show, this script is called a pilot. Scripts can be written by individual writers or a whole team.
Once the script is written, the story idea is pitched to a team of executives, who will decide whether or not to make the show. If it is a script for a show already in production, the pitch becomes about story approval.
Once the script is finalized, the show is shot. Sitcoms, with a live audience, will rehearse during the week and then perform the episode one night for an audience. Scenes are often shot multiple times to get variety. Shows that have no audience are often shot over the span of a few days.
The footage from the filming is edited, and any special effects are added in. Sound is touched up, and the credits are added in. Now you have a completed episode.
Test It and Show It
If it is a new show, the pilot will be shown to a small test audience. If the audience likes what they see, the network is more likely to put the show on the air. If it is a show already in production, the final episode will be screened, approved and aired at its scheduled time.