Iron Man is the first movie in the Marvel Cinematic Universe (MCU). In the fictional world, Tony Stark (Robert Downey, Jr.) is heir to one of the biggest defence contractors, Stark Industries. He is a billionaire playboy philanthropist who happens to be an engineering genius.
During an attack meant to kill him, he was severely injured and abducted by the terrorists instead. In prison he meets a fellow captive, a doctor named Yinsen (Shaun Toub), who places an electromagnet in his chest to keep the shrapnel from reaching his heart. The terrorists who call themselves the Ten Rings commissioned the two to build a powerful missile in exchange for their freedom, but the two spend their time building a power armour so they could escape.
During the escape, Yinsen is killed and Tony goes back to his life shaken by the events. More deceptions led Tony to amplify the suit using the electromagnet, which he uses to fight against his enemies. He is one of the few Marvel heroes whose alter ego is revealed to the public.
The movie is a huge success which and it made Iron Man a popular Marvel character while paving the way for Downey to become of the highest paid actors in Hollywood. Iron Man was released in 2008 and was followed by Iron Man II in 2010 and Iron Man III in 2013.
Iron Man is also part of The Avengers with movies released in 2012 and 2015. He was also featured in Captain America: Civil War released in 2016. In that Captain America instalment, he recruits Spider-Man (Tom Holland) to join briefly in the fight. In Spider-Man Homecoming released in 2017, he is also seen mentoring the young Peter Parker, who is just beginning to discover his abilities.
Speculations about a fourth Iron Man standalone film continue to make the rounds, but no official confirmation nor disapproval has been made.