Battle Creek is set outdoor in a tiny canyon featuring two symmetrical bases that are separated by a small creek. Battle Creek is one of the smallest multiplayer maps in the game and is well-suited for two to eight players.
     
  Blood Gulch is set in an enclosed, symmetrical canyon with a base at either end and an open field between. The level supports vehicles and is recommended for 4-16 players. The level is almost entirely void of life, save some sparse grass and bushes. Blood Gulch is easily the most famous multiplayer level from the original Halo.
     
  Boarding Action is set in space above the Soell system.
     
  Chill Out is one of the smallest multiplayer maps in the game. Chill Out is well suited for small, usually team-based, games between two to eight players.
     
  Chiron TL-34 was designed to train those who were in close combat within Covenant ships, which feature narrow spaces, hence the enclosed hallways of that particular area of the training station.
     
  Damnation is one of the few non-symmetrical maps and incorporates both a high and low flag base, providing heavily vertical gameplay. It is highly popular on the Oddball andTeam Slayer gametypes.
     
  Danger Canyon is somewhat similar to the Halo and The Silent Cartographer levels in single player Campaign of Halo One.
     
  Derelict is set aboard a Forerunner space station apparently in orbit around Threshhold, as the planet is visible through the windows, as well as the moon Basis. It is cataloged by the UNSC asDeep_Space Anomaly #0198. It is a very small level that is best suited for 10 or less players, as more can become extremely chaotic unless that is the desired effect. 
     
  Infinity is the longest multiplayer map, being a long canyon shaped in an ∞ (Lemniscate or "Infinity") symbol, hence the name infinity. It's considered one of the best maps for the race gametype.
Other Sources of Information
http://en.wikipedia.org/wiki/Halo_(series) https://www.halowaypoint.com/en-us
http://www.halopedia.org/ http://halo.wikia.com/wiki/Main_Page