Lots of different sources produce light ... Light can also be produced by stars, fires, light bulbs, torches, street lights, glowsticks, candles, lasers and even blue light from smartphones.

You might have learned in school that Thomas Edison invented the light bulb, but the truth is much stranger (public domain) It has been known for a long time that passing a current through a wire ...

You can easily create Schedules so that bulbs inside and outside your home go off as needed. Or have them light automatically when someone arrives home and turn off when everyone leaves.