It’s no secret to comicbook fans that Jean Grey is one of the most powerful mutants around, but they took it up a notch in the films.
The movies did this by combining Jean Grey and the Phoenix. In the comics the Phoenix possesses Jean, strengthening her powers. In the films, she’s born with the Phoenix power. Not only did we see this in X-Men: The Last Stand, but she also unleashes the Phoenix in X-Men: Apocalypse.
In the comics, Edwin Jarvis was simply Tony Stark’s butler (Tales of Suspense #59) before becoming the butler for all of the Avengers. In the Iron Man films, JARVIS (now all caps) becomes Tony’s AI assistant, able to help him build his suits and complete missions before he would become Vision in Age of Ultron.
In Age of Ultron and Captain America: Civil War, Vision is powered by an Infinity Stone, unlike the comicbooks where he is instead powered by a solar jewel. While similar, the Infinity Stone grants him much stronger abilities.