Goku:
Goku is the main character throughout the series. He is a lower class Saiya-jin who is sent to Earth as a baby to get it ready to sell, but he falls down a mountain and hits his head leaving the mission aside he wonders through the woods and is found by a man named Gohan. But one night a full moon turns Chibi Goku into an Oozura and kills his father. From then one we see. Goku wondering through the woods until Buruma finds him. He also meets Kurin and they become come good friends. And together so go in search of the Dragonballs. Goku grows up into a strong and brave warrior. He marries to Chi-Chi, Ox-kings daughter. Together they have 2 children, Gohan and Goten. Goku has saved the universe from almighty Freeza as we see in the Namek saga. He is also the first Saiya-jin to turn Super Saiya-jin.(I think that Brolly might have been though not too sure about that.) and not to mention givivg Majin Buu a headache. Goku is also the first to reach SSJ3 and to become a Golden Oozura. Goku joins the Special Forces(The Z Fighters) and helps to protect the Earth from evil.

Gohan:
Goku and Chi-Chis first son. Gohan is a very strong and brave fighter as a child and his power even surpasses his father at times. Gohan looks up to Piccolo. Piccolo trained Gohan for a full year before the arrival of Vegeta and Nappa. Piccolo even gave his life for Gohan in battle. He wears similar clothes to Piccolo and wants to be just as strong as him(And he gets a lot stronger than him too!J) Gohan has a phenomenal power at an early age. Gohan is also the first to go SSJ2 and beat the heck out of Cell.!! He has potential to be the strongest fighter in the universe but his power comes from within and is only unleashed when he gets mad. When he gets older he joins Orange Star High School where he meets Videl. They marrie and have Pan.

Goten:
A mischievous boy, the second son Of Goku and Chi-Chi. He is best friends with Trunks and they can fuse together to make Gotenks. Goten is always getting in trouble and messing about. He has great potential to become very strong but does not reach that because he is too naughty. He is the youngest to become a Super Saiya-jin at 7 years of age.
Pan:
The daughter of Gohan and Videl, she is probably the strongest female fighter on Earth. She is born 7 years after the Buu saga. When she hears Goku(her grandfather) and Trunks talking about going into space to search for the Black Star Dragonballs she follows along.

Vegeta(Bejita):
Vegeta is first introduced into Dragonball as a villain. He hates Goku for the simpl fact that Goku is stronger than he is. Vegeta is the son of King Vegeta who rules Planet Vegeta(the Saiya-jin homeworld). Vegeta is stolen from his father by Freeza. Freeza brings him up as an evil person who is pitiless and has no remorse. Vegeta is after the Dragonballs for one reason, immortality. Vegeta finds out about the Dragonballs on the Planet Namek, were he meets Goku again and believes that Goku is a Super Saiya-jin.(Although he isnt yet, hes only very strong!) Vegeta thinks that he is stronger than Freeza after Kurin wounds him. But unfortunately he is not. Vegeta is killed by Freeza but is revived when the Earth Dragonballs are used to wish everyone back to life that was killed by Freeza. Two people, Majin and Bebidi, possess Vegeta. He also becomes a Super Saiya-jin. He becomes purely good when he acknowledges that Goku is stronger than he is in a bad situation. So therefore when all the good people are wished back, he is to. Vegeta is marries Buruma and together they Have a son, Trunks.


Trunks:
Trunks is the son of Buruma and Vegeta. Mirai Trunks is from a chaotic future, Mirai (Future) Trunks comes back in time and kills Freeza bot with ease , along with his father, King Kold. He warns the Z fighters about the future, and the androids he also tells them how they can prevent any of it from happening. In Trunks' future, two androids, Numbers 17 and 18, are destroying Earth. Surprisingly, he can also become a Super Saiya-jin, making him the second (in our timeline, that is) to become one. This really makes Vegeta mad but he finds out that Trunks is his son and he is proud.. When he goes back to his timeline for the second time, he finds that history had not changed. But he is a lot stronger so he kills androids #17, #18, and even Cell. The Trunks of the normal Dragon Ball timeline, is best friends with Gokou's son, Goten. Trunks and Goten can fuse to become Gotenks a very strong yet over confident being with hilarious attacks.

Brolly:
Brolly is also a Siya-jin who is sent from Planet Vegeta as a baby to Earth. Brolly gets his huge KI from having to manage his crib mates noise(Goku). For that reason he despises Goku. Brolly has a huge power and I think is the original Super Saiya-jin . He confronts Goku and tries to kill him but he is killed by Goku, or thats what we think. He appears again later in movie 10, and killed again for good. But he is cloned by some mad scientists in movie 11.