Quite often "security lamps" are sold with PIR (movement detector) or photocell (light sensor) built into them. But they are available separately. Examples on my TLC link above.
For example, if you have two or more lamps around your path or door, you might want them all to come on together.
So you can buy a separate PIR and have it wired to control any number of lamps. The ones sold separately tend to be better quality than the ones built into lamps, and they enable to buy any shape, size or style of lamps that take your whim.
There are some quite high-current PIRs and Photocells available, for people who have a larger home and have an array of floodlights, but a large building like a castle or cathedral might better be wired up by an electrician using a contactor.
BTW, I think a porch light is better arranged to come on at dusk, and go off either at dawn, or at, say, midnight, rather than switch itself on and off every time somebody walks or drives past. There are light switches designed to do that automatically.
A porch or path does not need a dazzling light. My own porch was too bright at 8W energy-saving and now has a 4W LED which costs approximately nothing to run.