Greet'ns. This was something I started idly wondering about a little while ago, and thought it might be an interesting question for everybody to answer for themselves and in turn discuss, because Halo as a series has never been totally consistent--no, I'm not trying to rag on Bungie vs 343i here--going back to the divide between the first books and games in where their focuses were. The Fall of Reach novel, for example, was about the Chief's military upbringing almost a la Ender's Game and the steadily-losing Human-Covenant War. But then, Combat Evolved doesn't have the Chief's personal backstory even enter into it. It's about traversing fantastic alien landscapes without knowing quite everything about them, setting you up for the reveal "Halo is a weapon." From there, 2 and 3 bring the alien perspective and Cortana and Chief's relationship more into light, and the Reclaimer trilogy is pulling Forerunner remnants more and more to the fore. I suppose I'd almost not consider ODST and Halo Wars here because they're not so much the main story being told, but the books I'd count far more relevant, but too numerous to list.
But there are all these conflicts going on out there--insurrections against a controlling central government, humans fighting, cooperating with, and trying to put past conflicts to rest with alien species, and the leftover artifacts of galactic civilizations that fell long before our time. So I guess what I'd ask to all of you is what common threads do you see? Each of us has different levels of exposure to Halo and its media, so what different takes on it do we have? What's Halo about to you?