The Human Torch was an android who could fly and, due to an error in his design, could envelope himself in flame at will (initially, he had no control over the flame, and would catch fire whenever he was exposed to oxygen).
In between fighting crime as the Human Torch, he pursued a normal human existence under the name of Jim Hammond.
The Human Torch was one half of the first major crossover in comic book history, a two-issue battle between him and the Sub-Mariner that appeared in Marvel Mystery Comics #8-9.
After appearing in a wide variety of comics during the 1940s, the Human Torch fell victim to a general slump in the superhero market and disappeared for most of the 1950s. When the market revived, Marvel Comics introduced a new Human Torch (see below), and the original was not seen again apart from an occasional guest appearance.
As a result of the cosmic ray exposure during the space flight he took with his sister, Susan, Reed Richards and Ben Grimm, he gained the most spectacular set of powers. Namely, he can harmlessly envelope himself in flame at will which allows him to fly, shoot flame offensively and absorb heat energy.
As the youngest member, he has proved the most impestous and was given to many of the concerns of teenagers. This includes a playfully antagonistic relationship with Ben Grimm (now, as a result of his own cosmic ray exposure, the Thing). This hit a low point when Johnny fell in love with Ben's old flame, Alicia Masters and married her, only to learn that she was a Skrull imposter named Lyja.