Ogres appear alone or with Green Ogres, Creeps, or Hyenas. They're found in the beginning and middle of the game.
At low levels don't go against two of these. Once you get some Short Swords or FIR2 you'll be good to go though. Also, being a member of the Giant category, the Giant Sword is more effective (in the WSC version), not that it matters since you should be able to kill them in one hit by the time you get it anyway.
Ogres have the same name in every version. Ogres can be found in classic fairy tales, Disney cartoons, Shrek, and games like Dungeons & Dragons and Warcraft 2. Ogres return in FF2, FF3, FF4, FF9, and FF10. You can also find an axe called Ogre Killer in FF4, and a sword called Ogre Nix in FF6 & FF7.