The series takes place after the events of the film Avengers: Endgame
It's Marvel Studios' first TV series - "Wanda Maximoff/Scarlet Witch" played by Elizabeth Olsen and "Vision" played by Paul Bettany, are two super-powered beings living idealized suburban lives in the town of Westview, who begin to suspect that everything is not as it seems.
Wanda Maximoff/Scarlet Witch is an Avenger who can harness magic, engage in telepathy and telekinesis and alter reality
Vision is an android and former Avenger created using the artificial intelligences J.A.R.V.I.S and Ultron as well as the Mind Stone
Kathryn Hahn plays "Agatha Harkness" - one of the original witches from Salem and one of the Earth's most powerful witches. Agatha is Wanda's mentor in the Marvel comics
WandaVision takes place throughout several different decades, including scenes set in the 1950s inspired by The Dick Van Dyke Show and various classic sitcoms, right the way through to modern day.
WandaVision, the original series, is exclusively streaming on Disney+ from January 15th.