C-3PO and R2-D2 are two iconic characters from the Star Wars franchise. They are both droids, which is a term used to describe robots in the Star Wars universe. C-3PO is a humanoid ROBOT with a golden exterior, while R2-D2 is a small, astromech DROID with a domed head and cylindrical body. Both characters are beloved by fans of the franchise for their unique personalities and loyalty to their masters.