The Galactic Corps are a combined militia and police force; neither heroes nor villains but sometimes both. They're controlled by an elite of human politicians who have little but self-interest at heart. They're happy to let the Corps do good work such as rescuing disaster victims but only if it does not conflict with their own interests.
The Corps are basically the best and worst of humanity - striving for a better world but only for their masters. The Corps view Traders with disdain and will often treat them as criminals, using any excuse to engage. Towards the more affluent areas the Corps are better trained and equipped, whereas discipline out in the sticks tends to depend entirely on the local director; a lazy corrupt director will lead an inefficient band of bullies rather than a well-oiled machine.
The origins of the Galactic Corps are hazy but most likely it started as a private security firm with military leanings. Over time the general populace has accepted that the Corps are the galaxy's army ans police rolled into one, but in fact the Corps has no true official standing. The GCC tolerates the Corps rather than condones it, understanding that it is too large an organisation to take head on. The Corps does help maintain order, particularly against the Purge, although its rough edges anger civil rights activists and often draw bad publicity.
Squads going into action tend to be small and tightly ordered, consisting of a team of Guards, a Juggernaut and a Director, although the numbers of each are often bolstered for certain situations.
Juggernauts are powerful and heavily armed; the hammer of the Corps used to bludgeon and punish any disobedient populace. They are often large men who have been chemically enhanced or have a mutation, normally in favour of size and aggression at the expense of intellect.