Gohan becomes the main character after the Cell Saga (during this time Gokuu is "dead"), assuming a diferent identity with which he fights against Crime (he was first known as The Golden-Haired Warrior - he gets his "instant" costume from Bulma (when pressing a button on his watch an instant costume appears), using his transformation into Super Saiyan and sunglasses as a facial disguise, but because the disguise isn't very good he finally decides to turn into: The Great Saiya-man, using this time a helmet; he spends most of the time praticing poses instead of fighting crime...
At the end of the series Gohan becomes a scholar in a local college (he looks a little nerdy). He joins (I don't really know if they marry) with Videl (also known as Beederu). This union results in a daughter, Pan.
Son Gohan is Goku's first son. At the end of the series he was 26 years old but in this picture he is 9. For a short while after the second time Goku died in the series, Gohan became the primary character. Gohan is the most powerful non-fused character in the DBZ world, but lacks the love of fighting his father has and thus rarely uses his full strength. Gohan is a very good-natured boy and unlike his father, hates fighting, although for a while he was more powerful. He is very polite towards just about everyone except to his enemies, and when he's pissed off. Gohan is very bright and studies very hard, although this is somewhat due to the wishes of his very strict mother... Gohan is the first character in the series to have gone Super Saiyan-2, during the Cell Game; the power of his anger was kindled by watching his friends get beaten up, and the death of Artificial Human #16 sent him over the edge. It was roughly at this time that the series switched main characters from Goku to Gohan.