Some shots need a sun. Sadly the sun is not at the optimal angle at all locations. Heck, if you are indoors (say at your studio) there may not be a sun at all. This is why there is a need to create a fake sun.
Creating a fake sun is easy, once you know the light qualities of the sun, and really, there are only two of those. It’s (1) small, and (2) orange. Actually, the sun is not really that small, it’s huge, but it is so far away that it small in relation to our field of view. The sun is actually not orange either, it’s white, But the light that gets here to earth becomes orange after it goes through the atmosphere. So while the Sun is neither small nor orange, it is small and orange for us. And this is the light we are going to reproduce.