AR111 / ES111 / QRB111 / PAR36 Downlights which are generally used for accent lighting.
Due to their flat beam angles of commonly only 24° they are more likely to live up to a spotlight's name than any other reflector lamp.
Please consider: There isn't any proper standard. AR111 lights come in a multitude of different technologies (Halogen, Halogen Metal Halide, LED and even Compact Fluorescents), beam angles, voltages, recess depths and connection types (G53, GU10/GX10, GU5.3/MR16 etc.). Take care that you buy the recommended bulb.