The Avengers's worldview is the Marvel Universe, including Raytheon, Team USA, Iron Man, Hulk, Fast Silver, Hawkeye, Scarlet Witch, Fantastic Four and X-Men, but all of them belong to the Marvel Universe (except Wolverine). Of course, Spider-Man is a hero in the Marvel universe and a member of the The Avengers (belonging to The Avengers on the west coast). In comics, there are some Avengers. However, there are only seven people in the movie. Although Spider-Man has also made movies, his film copyright is attached to Sony, so he can't make movies with people whose copyright belongs to Marvel Comics, such as Iron Man.

Batman's cosmology belongs to the DC universe (unlike The Avengers, who can't make movies together), and Superman, Green Lantern and so on. Although they all made movies, their copyright belongs to DC like comics, so they are not in The Avengers.

Hope to adopt, thank you.