Ogres are one of the smaller varieties of Giant. In Eberron, they are known to reside on multiple continents.
Like humans, ogres originated on the continent of Sarlona, in the region known as Borunan. Today, the ogres there are born and raised to serve their Inspired rulers, much like the local humans.
Presumably, ogre slaves were brought to Khorvaire with the human migrations, eventually escaping. In 998 YK, Khorvairan ogres live mostly in the Southwestern portion of the continent: Breland, Drooam, and nearby nations.
Ogre = Laborers in Sharn & Riedra, heavy infantry in Droaam.
Ogre-Mage/Oni = Powerful, with innate magical abilities, they are either on the run from Riedran authorities or are among their most dangerous servants.
Eneko = True-breeding cross of Half-Giants and Ogres or Ogre-Magi; they live mostly in Syrkarn.