Gohan is the son of Goku and Chi-Chi from the series Dragon Ball Z. While his character starts out as a supportive role, he becomes very influential as the series progresses. The series follows him from infancy through adulthood.
Throughout the series Gohan's appearance goes through many changes. He is first seen as an infant, and then as a toddler with the Saiyan monkey tail. As he matures he looks more like his father, though he has Chi-Chi's light complexion.
Being half human and half Saiyan gives Gohan a unique power. This has a huge affect on his personality. While the Saiyan race is a strong, militaristic society, Gohan's human aspect gives him mixed feelings about fighting. He is depicted as a studious and introspective character. However, when forced to fight he uses his great power to protect his loved ones.
Goku dies quite early in Gohan's life. His training is left to his mentor Piccolo. This relationship is strained at first, especially since Piccolo was once Goku's rival. However, in time both characters are influenced by one another. A deep friendship develops, which leads to Piccolo sacrificing his life for Gohan.
It becomes clear that Gohan has an intense power dormant inside him from the time he is a toddler. While seemingly limitless, it takes years before he is able to control and use this power at will. In the beginning it is only accessed when Gohan goes into a deep rage. By the time he is a young adult, he is able to use the power at will. This makes him arguably the strongest warrior in the Dragon Ball Z series.
Gohan's power is truly seen when he fights the evil Cell. At this point he has surpassed his father, as well as the other Z-Fighters. While Cell is distracted by Vegeta, Gohan pours all of his power into a final energy attack. This destroys every part of Cell's body, finally putting an end to the battle.
While in high school, Gohan meets his future wife Videl. They eventually have a daughter named Pan. At the end of the series Gohan is able to pursue his scholarly interests. He lives the end of his life in peace, and dies happily of old age.
Gohan is one of the most complex Dragon Ball Z characters. He struggles to balance his high intellect with the brutal power of the Saiyan race. Gohan proves himself by saving Earth and becoming one of the most powerful Z-Fighters.