If the common dusk till dawn photocell (resistor?) turns the power ON when dark and OFF in the light what type of photocell would be used to turn the power on when in light (daytime) and then power off when it gets dark (night)? Is that a photodiode? Thanks

You can design the device to work however you want. You will not do it with one single component however.

Meaning you could use EITHER component to do EITHER as long as you design it to work that way. My point being while I am sure I get the point you are getting at which is correct...just that your examples could easily be wrong as an analogy. Example being instead of turning on a light bulb, the same circuit could energize a normally closed relay, turning off whatever is plugged into it.