Backlighting is where you photograph your subject with the light source behind them. The light is back behind them.
Front lighting is the opposite, where you are photographing your subject with the light shining directly on them. So the light source is actually behind you, as the photographer.
The way you choose to light your subject is 100% a personal choice. Different people prefer different looks, and that's all part of each of our own tastes and style.
I almost always choose to backlight my subjects. I prefer the look of it, it's easier on my clients, and it's just an all around more flattering look, I think.
Others might disagree.
Here's an example of the difference between backlight and front-light using the only photo-model I had during the time I was writing this post - my tripod. The photo on the left has the sun behind the tripod, which is backlighting the subject. The front of the tripod has even light all over it, and if that tripod was a person with eyes, they wouldn't be squinting because they would be facing away from the bright sun.
It's a personal preference - which do you prefer?