What do you call the stores on the front of a building(department stores or apartment) (on ground floor usually) that face the roads with its own entrance?
Though not really obscure, the technical terms are storefronts and shopfronts. Usually this refers to the bottom floor (sometimes bottom few floors) of commercial real estate where the shops are leased from the main structure and have an on-street presence.
While some buildings have multiple stores, the storefronts are the ones that face outside/or main hallways and have display windows. Inside they are just shops, stores, bodegas, and retail space if they don't have display windows.
More about them here on Wikipedia.