Prior to the development of probots, remote probes had done the majority of mechanized exploration. These were comparatively simple machines, equipped with onboard computers and sensors. However, they were programmed to follow a carefully limited set of parameters and lacked the intelligence for true initiative or understanding. The first probe droids were marvels of technological achievement, a single unit capable of doing the work of a team of scientists. Incredible amounts of unexplored territory were thoroughly mapped and charted by these machines during the days of the Galactic Republic.