Goku is a Saiyan Raised on Earth. From a very young age he learned many martial arts techniques from many masters. Over time Goku learned how to make techniques like the Kamehameha powerful enough to destory planets. Goku is the defender of earth and he will not let anyone destroy his home planet. Through the power of Ki he can create Ki Blast that destory his surroundings. Goku is pure of heart.