Once Marvel Studios launched the Marvel Cinematic Universe, one of the behind-the-scenes topics that became of particular interest for fans was contract lengths.
Tom Holland has only made one appearance so far as Spider-Man in Captain America: Civil War, but his performance has made his upcoming solo film Spider-Man: Homecoming a highly anticipated project.
I do know I have three Spider-Man [appearances in other] movies and three solo movies contracted.
All of the original Avengers had these deals and Marvel has continued this structure with some of its newest members too.