What I have learned from videotaping horses.on June 3, 2018 at 2252
The sun is very bright, but the sun is very small. All the light from the sun comes from one very limited area, everything else is reflected.
Think of the Sun as a giant onion, with invisible layers radiating out from the center . Only things that fall within the angles of those layers of the onion fully reflect the Sun. Everything else is in some manner of shadow.
This means that, when you are outside in full sunlight, practically everything is in shadow. This is especially true when you are looking towards the sun.
People, when they are facing the sun, tend to squint. This means that you have to shoot them at some other angle. For everything else in the world, if you want it in full sunlight, you have to have the sun at your back. When the sun is at your back, practically everything is well lit. If the sun is in front of you, everything is in shadow.