Droid brain
From Wookieepedia, the Star Wars wiki.
A droid brain was a computer that was the central processing area of a droid. Without a droid brain, a droid was useless, and could not function. They were also used in droid starfighters.
Another use for droid brains were spaceships. In spaceships, droid brains were used for operating and navigating the ship. The Millennium Falcon for instance had three different droid brains, which caused the Falcon to have schizophrenic arguments with itself.
