Droids range from simple machines to complex, sentient artificial beings. They are generally treated as mere utility devices, reguardless of the level of intelligence, and most citizens ahrdly notice them. Memory wipes, which are customarily performed when a droid aquires a new owner, can delete filed information or completely erase a droid's stored experiences. When "zeroed" this way, even sophisticated droids may be rendered barely self-aware. If allowed to build experience between memory wipes, some droids seem to develope individual identities and even idiosyncratic personalitties.
Astromech Droids Unipod Droids Battle Droids