The Providers was a colloquial term given to three non-humanoid beings who controlled the planet Triskelion in the M24 Alpha trinary star system. They appeared as disembodied brains contained in a device giving them life support and communication abilities. When Captain Kirk speculated in their presence in 2268 that they were the result of "primary mental evolution" they corrected him, stating they'd once had humanoid form, but after eons of devoting themselves exclusively to intellectual pursuits they had evolved into their present form. The aliens called themselves "Providers" because they believed the term was easier for the limited intellects of their slaves, whom they called thralls, to comprehend. If their race had another name, they never revealed it.
The Providers controlled an immense power station, which they concealed a kilometer or more beneath the surface of their world. They could create and project their voices anywhere on Triskelion, and they controlled a transporter based on light that had a range of light years and operated nearly instantly. They could manipulate energy at least to the extent of neutralizing a starship's power systems. They provided sustenance and other basic needs to the thralls, and could punish the thralls directly or through their proxy, Galt. They evidently possessed significant planetary defenses, for they did not regard the arrival of the USS Enterprise at their world as a significant threat, stating that they could destroy it and make the incident appear to be a magnetic storm.
To amuse themselves, the Providers captured humanoids and forced them to fight while they placed wagers on the outcome. Inasmuch as such fights were often to the death, they required a steady supply of humanoids. To obtain it, they practiced humanoid husbandry with their existing stock (selecting breeding partners) and kidnapped suitable humanoids from elsewhere in the galaxy via their powerful transporter. They claimed to use only "inferior specimens" but considering their own vast intellect and concomitant high opinion of themselves, it is likely they regarded all other forms of life as inferior to their own. (TOS: "The Gamesters of Triskelion")