In post-production the film is edited, special effects and sound added, and titles created. We say that film is a director's medium because the director working with the editors has the final say as to what the film will look like. The production of television is a little like both of the above, depending upon whether it is a TV movie or weekly series. The television movie goes together in the same way a theatrical film does. But a series is much like theatre, only moreso.
Series television has a definite target date, but has a much shorter time span to reach it.
The fact that an episode is only either 23 or 48 minutes makes this possible. For example, a half-hour sitcom may be written in 48 hours over a weekend in time for a Monday morning table read. During the rest of the week the writer and staff do revisions, the cast rehearses, and any new sets required for the episode are built. Meanwhile, the staff and writers are also plotting out the next script. The writer goes home to write a draft of the next week's script as the cycle continues.