Many of the skills and abilities shown in Dragonball are performed using the advanced knowledge of Energy manipulation. In DBNU, skills are performed using Ki, Energy, or Mana.
Some beings instead have an Energy supply. Androids have an internal battery that allows them to generate energy for skills. Fierian Demons, lacking a truly physical form, also use basic 'Energy' rather than 'Ki' energy.
Wizards are unique in that they possess a pool of Mana that they use to perform skills and spells.