A connector is mateable with a mating connector along a first direction. The mating connector comprises a plurality of mating protrusions. Each of the mating protrusions protrudes along the first direction. The mating protrusions include a first mating protrusion and a second mating protrusion. The connector comprises a terminal and a holding member. The holding member is provided with a plurality of receiving portions. The receiving portions include a first receiving portion and a second receiving portion. The first receiving portion is opened in each of the first direction and a second direction which is perpendicular to the first direction. When the connector is mated with the mating connector, the first receiving portion receives the first mating protrusion to regulate a movement of the first mating protrusion. The second receiving portion is opened in each of the first direction and a third direction. When the connector is mated with the mating connector, the second receiving portion receives the second mating protrusion to regulate a movement of the second mating protrusion.