Dende is a young Namekian and the 108th child of the Great
Elder. He is a healing Namekian and during the Freeza saga helps out Gohan
Krillin and Bulma after Gohan and Krillin saved him from Dodoria when his
village was attacked. He heals the Z warriors while they are fighting Freeza
on Namek, but gets killed by him. He is brought back to life when all the
Namekians are wished to a new planet.
In the Cell saga since Piccolo and Kami fused, a new Guardian was needed on
Earth. Dende, being a healer also meant he could create Dragon Balls, was
asked to be the new Earth Guardian. Dende created a new, more powerful Shenron,
and a new set of Dragon Balls.