What is a film release window?
A release window is a period when a film is offered through a particular channel. Theatrical exhibition, digital rental and subscription streaming can have different start dates.
Reading a release announcement
A studio announces a cinema opening on 5 March and a digital rental on 2 April. That establishes two dates for the named market. It does not establish when a streaming subscription will include the film, or when viewers elsewhere can rent it.
Does a release window mean exclusivity?
Only if the rights or announcement say so. Look for the territory, service, format and any exclusivity language. A rental becoming available does not itself tell you that cinemas have stopped showing the film.
Read the source
Disney’s annual report: Content Sales/Licensing