Back in April 2013 I posted about the great Superium that runs vast sectors of the galaxy.
And if sci-fi shows like Firefly, Star Wars, and Star Trek (or just plain old good storytelling) have taught us anything, it's that the great and powerful government needs some upstarts to maintain a standing conflict.
Thus I have settled on the Superium's adversaries - the C.A.P. (Confederation of Allied Planets).
Obviously I couldn't use "the Federation" without immediately conjuring Star Trek connections. Besides, I don't particularly like the notion of a federation. When I think of the Fed I think of: over-reaching, arrogant, taxation, and otherwise meddling for meddling's sake.
But I also couldn't call it "the Confederacy" without blundering into associations with the South in the U.S. Civil War.
Perhaps, like myself, you need an easy comparison between a Confederation and Federation.
Think of the United States when they were in fact just that. United states. Before the formation of the federal government, the original colonies chose to operate together for a greater good/benefit.
A confederation is voluntary. A federation isn't necessarily.
A confederation lacks a powerful core, instead being governed by a council of sovereign entities.
A federation typically has a centralized "seat of power" like a Presidency or Chancellor.
In a confederation the system only lasts so long as the various parts decide to participate. This hopefully leads to more cooperation because the entire thing crumbles if agreeable terms aren't met and maintained for everyone.
In a federation, the votes are tallied and the law becomes the binding "agreement" which must then be enforced and upheld, even if you were one of them that got out-voted.
A confederation grants a certain amount of autonomy to its member states to govern themselves in matters of customs, trade, law, etc. They operate together in terms of protecting the whole by protecting the parts.
A federation typically controls several aspects of its participants from economic concerns to housing, travel, and education. A norm/average is expected to be upheld for everyone, like it or not. And certain cities or regions are given priority status, while others are ignored.
I was thinking of calling it the Coalition of Allied Planets, but that is much too informal to operate in large numbers. A coalition is generally on a much smaller scale, say a dozen individuals. They work together for a short time to meet a short term coal. Think of it like a small community of farmers all pitching in to plant, tend, and harvest a variety of crops to be held in a central storehouse. That might help them last through a few hard winters, but it's not necessary forever.
So the background could be that the C.A.P. started as a loose coalition to repel a common threat - pirates, slavers, smugglers, what have you. Over the years they realized the benefit of continuing to work together in defense of their homes and trade routes. Gradually they formalized into the Confederacy of Allied Planets. It maintains peace among them as neighbors because a war between them would harm both and benefit none.
There you have it, the Confederation versus the Superium.