Battle droids
Definition
Battle droids are the mass-production combat units of the Separatist alliance and earlier Trade Federation. The line ranges from the lightweight B1 infantry droid to the armored B2 super battle droid, the rolling droideka and the elite commando droids.
Context
Battle droids appear from The Phantom Menace through Revenge of the Sith and dominate the ground fronts in The Clone Wars. They are produced on factory worlds like Geonosis and are controlled through central command signals — which is why the destruction of the droid control ship at Naboo ends the battle instantly.
Why it matters
Battle droids are the visual shorthand for the Separatist threat: cheap, expendable, everywhere. Their dialogue in The Clone Wars gives the war comic relief, but droidekas and commando droids show why the Republic needed a clone army at all.