A "night shot" is whenever a shot is done to make the scene look like it took place at night. Given the expense of shooting and properly lighting a scene that takes place at night, it is rarely actually done so during the actual nighttime. 

From the clips below, you can see that there are multiple ways to combat this problem. 

This clip from Jean Cocteau's La Belle y Bete uses a soundstage. Using a soundstage, it allows him to control the environment instead of relying on the elements to fit his vision. To most uneducated eyes, the difference between this soundstage and the outdoors is not apparent. However, you can tell it is a soundstage thanks to the clustered framing, and the spotlights hidden to mimic moonlight. 

This clip from Federico Fellini's Amarcord uses the lighting sources of the location to light the scene. Fellini has the neon lights in the set to seemingly light this shot while also using secondary lighting sources to make sure proper exposure.