A log line is one or two sentences that describe what your movie or TV show is about. The best log lines not only convey the story, but they also convey setting and character.
Romeo and Juliet: In medieval Italy, a young man falls in love with the daughter of a sworn enemy. The two lovers elope with tragic consequences.
Jurassic Park: A team of researchers and a family struggle to escape and island park filled with genetically restored dinosaurs.