Missions.
No, Halo Reach shows what happened before Halo 1. In fact, in one of the missions in halo reach, you can see Master chief
In my opinion, they're a lot longer than Halo 3's.
if you mean co-op then yes you can
No you can't create your own missions. The closest thing to that is Forge.
Yes. Halo 3 is better. There is a book called Halo fall of reach and the game halo reach went totally off the storyline from the book
It is called active camo in Halo Reach, you can find it on loadout screens in firefight and matchmaking.
There is HALO 3 O.D.S.T (recon) and a new game called halo reach.
Halo: Reach comes with a built-in map editor called Forge Mode. You can access this from the main menu of Reach.
it called Halo Reach
only one called "installation04"
There is no Champion rank in Halo Reach. In some game types however, there is a weapon set called Champion that is available (i.e. such as in Invasion).
It just depends on what trailer. But the campaign trailer #1 is part of the HALO Reach soundtrack and the song is Lone Wolf.