With the exception of the uncommon hair colors and occasionally odd features (ranging from longer lifespans to werewolfism), Dragon Ball humans are identical to their real-life counterparts. Humans in Dragon Ball seem to be able to utilize or be affected by certain elements of magic. Akira Toriyama himself has admitted to lack of forethought or planning when it comes to the details of Dragon Ball's story, which accounts for some of the strange occurrences. They have been seen in every DB series.
Dragon Ball anime seriesHumans have a large military, which has appeared through out the series, mostly consisting of ground troops, tanks, fighter jets, and large naval ships. Earth's military usually appears when attempting to defeat many of the villains that cause massive damage to the Earth (examples being Cell and Majin Buu), but are always easily wiped out without causing any form of damage to the super villains. It could be assumed that large scale wars have taken place in the Dragon World, much like they have in the real world. However, since the Dragon World is united into a single, global monarchy, it is unknown what purpose the military serves when villains are not terrorizing the Earth that police cannot handle. It may be possible that King Piccolo's original appearance some 300 years before the events of Dragon Ball encouraged the then-king to create a military for just such purposes.
When compared to other races of Dragon Ball, some humans are significantly weak. It is said that a single Saiyan infant would be capable of destroying the average human population on its own (in fact, Goku was sent as an infant to Earth with that exact purpose). The only "normal" human whose power level was reported was a farmer, who Raditz said had a power level of 5. Though his level is probably representative of normal humans, there exist some particularly powerful humans, such as Master Roshi, Tien Shinhan, Krillin, Yamcha, Chiaotzu, Mercenary Tao, Master Shen, Yajirobe, Grandpa Gohan, Olibu, and Uub. Many of these human fighters are also Z Fighters. These few humans have learned to use ki and are among the strongest beings in the universe. Even with such abilities, this select group of humans are still considerably weaker than many aliens with the same ki-manipulation abilities. As stated in the manga, it is possible for any human to use their ki and gain powers like the Z Fighters. For example, Gohan easily teaches Videl how to use ki to fly.
Mr. Satan is considered to be the world's strongest man by humans due to him supposingly defeating Cell. In reality, he pales in comparison to humans like Krillin and Yamcha, who possess a lot more power. However, this is mostly due to the fact that these humans were granted more opportunities to increase their strength; for example, Krillin had his potential unlocked artificially by Guru and was trained by Master Roshi, and Yamcha trained under King Kai. All of the human Z Fighters climbed Korin Tower and trained under Kami, all things that Mr. Satan never had the chance to do.
It is also worth note that there are many strong humans who are also considered to be non-powerful. These include Nam, King Chappa, and Bora.
It has been shown that humans and Saiyans are able to produce fertile offspring (such as Gohan), but no explanation on the biology that permits this has been given.
Dragon Ball Online
It is explained in Dragon Ball Online that after Gohan writes the book "Groundbreaking Science" in 800 Age that unveils the secrets of ki control (Spiritualist) and advanced martial arts (Martial Artist), fighting becomes incredibly popular amongst the Humans, thus ushering a new age of Human warriors after the Z Fighters's end.
One section of Gohan's book explained that the dense material Kachin could be 'cut'; what this means is unknown -- if Gohan meant that it could be turned in weapons like swords or if it could be sliced through with a powerful enough strike, as he failed to do years earlier with the Z Sword. Nevertheless, this intrigued Trunks and Goten. Meanwhile, after reading "Groundbreaking Science", some humans became intrigued with the idea of channeling their ki energy into swords to increase striking speed and power. To instruct the newer generation of heroes, Trunks and Goten create the Kikoukenjutsu Sword School. In Age 820, remnants of Frieza's World Trade Organization attacked Earth, and were fended off by with much help from the Kikoukenjutsu Sword School.
Meanwhile, Master Roshi wished to return to teaching but felt that he was too old to possibly instruct fighting. In order to succeed his teacher, Krillin created the New Turtle School that emphasized on team work. While Krillin had fought many major battles alongside the Z Fighters, in his experience, he learned that team work was the most effective. But after learning of Kid Buu's defeat by Goku's Super Spirit Bomb, Tien's belief was that the greatest enemy could be completely destroyed with a strong enough ki attack. His New Crane School would emphasize on producing power ki attacks at the cost of health, rather than actual energy itself. The revival of these schools greatly aide the Humans in their conjoined efforts to stop the game's central villain, Miira, who seeks to obtain the DNA of Earth's greatest hero: Goku.
Humans are also capable of using the Super Saiyan transformation in Dragon Ball Online but only if the transformation is granted to them by Ultimate Shenron.
The most known Humans in Dragon Ball Z would be Yajirobe , Krillin, Yamcha, Tien, Chiaotzu, Bulma, Chi-Chi , Master Roshi, Launch , Videl, Uub ,and Mr. Satan . Some of those are the strongest Humans. The known Humans in the Dragon ball (series) would be Grampa Gohan, heros known 15/16 Humans are Goku Jr. and Vegeta Jr. Known 7/8 Human is Vegeta Jr.'s unnamed Mother. Known 3/4 Human Pan. Known half Humans are Gohan, Goten, Trunks, Bulla. Also famous is World Tournament Announcer.
Super Android 13!
Broly: Second Coming
The Return of Cooler
Wrath of the DragonBroly the Legendary Super Saiyan