His name (Gohan) is a homophone of “gohan” meaning cooked rice in Japanese. Akira Toriyama has a knack for applying food naming scheme in naming his characters, and he initially wanted Goku to be replaced by Gohan as the primary protagonist but later changed his mind.
He never had a static appearance throughout Dragon Ball Z because he started the series as a child and ended up as a married man with a child. Despite the changes in height and size, his main features remained the same, with black eyes and black hair. Facially, he is a replica of his father even though he possesses the light peach complexion of his mother. He also possesses an admirable muscular build as he is slightly thinner than his dad but taller.
His set of costumes were a bit inconsistent during his teenage days as we often see him alternate between a blue gi, school uniforms and an impressive Saiyaman costume.
He is a studious intellectual and shy child who lacks the fighting spirit exhibited by Saiyans. He however chose to fight with the Z Fighters and later became an important asset to the team. When he approached adulthood, he decided to be a scholar and finally became a successful one.
Despite having Saiyan blood running through his veins, Gohan does not exhibit the traits of a Saiyan. This is because he hates fighting and only does that in the extreme cases of necessity to protect his family. He is a kind hearted and a talented fighter just like his father. He also eats a lot and has a special bond with Piccolo (the former archrival of Goku).
Piccolo played a fatherly role to Gohan after the death of Goku and even trained him in the act of fighting as he sensed the boy’s potentials that could be used to save Earth from alien attack.