repair shop; repair workshop; garage
Refers to a place where repairs are done, such as a car repair shop, electronics repair shop, or general fix-it shop.
repairman; repair person
Refers to a person who does repairs, often used informally for someone who fixes things.
My car broke down, so I took it to a nearby repair shop.
He is a skilled repairman who can fix any machine.
修理工 is a standard term for a repair technician or mechanic, whereas 修理屋 is more colloquial and can refer to either the shop or the person.
Compound of 修理 (repair) and 屋 (shop, dealer, or person). The suffix 屋 is productively used to indicate a shop or a person engaged in a trade.