Our cameras are tools designed to record light. How we choose to use this tool is up to us. When I meet a client at a location, I arrive early to scout places that are suitable to create great portraits. Besides the background, light is the most important consideration.
Of course I can adjust my camera settings to photograph in any type of light. The problem with photographing people is that certain lighting situations can be more flattering than others and everyone wants to look their best. I cannot always choose the time of day I work, so sometimes (lots of times) lighting becomes a real challenge.
The two previous images are taken outside, early afternoon, where the sun is still bright in the sky. I would prefer that the background would not be brighter than my subject, but we don't always have that choice. I could use flashes or strobes to light the subject and balance the background, but I feel this defeats my purpose of using the natural outdoor light and why we are outside in the first place.
If I am allowed to choose the time of day, then it's going to be an hour or so before sunset, depending on the session. As the sun begins to set (we call this sweet light) it gives me the opportunity to use this soft direct light as I would a studio light (see 2 images above). I can also use that same light (in most cases) as a background if I want to use a flash to light the subject, or simply create a dramatic silhouette with an awesome sunset.