The Daggerfell Covenant is made up of the Orcs (also called Orsimer), Bretons, and Redguards -- although the latter two are coming out of something of a love-hate relationship, with a history of as much internal conflict as external. Apparently time does heal all wounds, though, because the three races have worked out a democratic system of mutual love and respect. The Orcs and Bretons call the beautiful land of High Rock home, while the Redguard are based in Hammerfell.
The Aldmeri Dominion is a more hostile power composed of the Altmer, the Bosmer, and Khajiit and intent on total domination. Also known as Wood Elves, the Bosmer call Valenwood home (surprise: It's a heavily wooded area) and enjoy tramping through forests, living in harmony with nature, and building cities in migratory trees. The Altmer, or High Elves, can be found in the little-known Summerset Isles. The Khajiit, who missed out on the alternative name lottery, live in Elsweyr, whose climate is ideal for the cultivation of Moon Sugar.
Got all that? Study up, there'll be a test. Feel free to read the full profiles, and keep an eye out for Ebonheart Pact information on Friday.