Iron Man
Tony Stark is a genius inventor, a tech wizard who used his genius to create weapons, selling them to the highest bidder. But after seeing first-hand the damage and pain those weapons caused, he took Stark Industries out of the weapon making business, and created the Iron Man armor to track down and destroy every piece of his technology that's being used to hurt people.
Captain America
Soldier. Idealist. Living Legend. Rogers is everything the old newsreels showed him to be... smart, courageous, a master tactician and incredible fighter. During World War II, Steve Rogers fought tyranny as Captain America using his peak human strength and agility, and his unique Vibranium alloy shield, to protect the free world.
Hulk
All the Hulk wants is to be left alone. But ever since the accident that transformed Bruce Banner into the incredible Hulk, the military has hunted him. To them, the Hulk is dangerous, the Hulk is a living weapon that has to be contained. And all this makes the Hulk ANGRY. The Hulk has been forced into a life of violence, of non-stop running and fighting.
Thor
God/Other Dimensional Being. Warrior. Thor Odinson is the literal Norse God of Thunder, one of the greatest warriors of all the Nine Realms. And while the rest of the Asgardian Gods have left Midgard (or 'Earth' as the mortals call it) behind, Thor has not. As Asgard's greatest warrior, Thor has vowed to protect all 'mere mortals' of Earth with his legendary hammer Mjölnir
Ant-Man
Scientist Hank Pym is one of the smartest men on the planet, specializing in biochemistry. He is a man of science, and never intended to become a Super Hero, but adventure tends to find him. Outfitted with his cybernetic helmet, the microbiologist Hank Pym can communicate with insects and shrink himself to microscopic scale as Ant-Man.
Wasp
The True Believer. The Life and Fun of the Team. Ditching her life as a wealthy socialite, Janet Van Dyne has used her bioelectric sting and her ability to shrink herself to become... The Wasp. Janet is Hank Pym's business partner. She's the one that makes his life possible, and funds his research and expeditions with her business and fortune.