A "crossover" film combines characters, settings, or franchises from two or more separate stories into a single narrative. This can involve different fictional universes or characters from different genres.

                          Common types of crossover films

1. Shared cinematic universes: These are large, interconnected franchises where character crossovers are a central part of the story. The characters frequently interact in "team-up" films or events.
2. "Vs." films: A common type of crossover pits two characters or franchises against one another in a direct conflict.
3. Guest appearances: A character from one franchise may make a small cameo appearance in another film, which confirms they share the same fictional universe.
4. Parodies and comedies: These movies often use crossovers for comedic effect, sometimes bringing together characters that would otherwise not belong in the same story

Notable examples of crossover films

                                                                                                   Shared cinematic universes

1. The Avengers series: A cornerstone of the modern shared universe model, this series from Marvel Studios features a massive crossover of superheroes from various individual films, such as Iron Man, Captain America, and Thor, who unite to fight a common threat.
2. Godzilla vs. Kong: Part of the MonsterVerse cinematic universe, this film brings together two iconic movie monsters from separate franchises to battle each other.
3. Glass: M. Night Shyamalan's 2019 film is a crossover and sequel to his earlier works, Unbreakable (2000) and Split (2016), combining the main characters from both stories. 

4. "Vs." films

5. Freddy vs. Jason (2003): Combines the horror antagonists Freddy Krueger from the A Nightmare on Elm Street franchise and Jason Voorhees from the Friday the 13th series into one film.
6. Alien vs. Predator (2004): Pits the Alien xenomorphs against the Predator hunters, originally a popular crossover idea in comic books.
7. Frankenstein Meets the Wolf Man (1943): This classic film by Universal is an early example of a cinematic crossover, bringing two of its most famous monsters together.

Guest and ensemble films

• Who Framed Roger Rabbit (1988): This technically complex film combined live-action and animation, famously featuring licensed characters from competing animation studios like Disney and Warner Bros. in the same scenes.
• Ralph Breaks the Internet (2018): The sequel to Wreck-It Ralph features cameos and sequences with an enormous number of intellectual properties, most notably with Vanellope meeting all the Disney Princesses.
• Space Jam (1996): This movie is a major crossover between Warner Bros.' Looney Tunes animated characters and NBA basketball star Michael Jordan, who plays himsel