“Weight Loss” is the term most people use to describe their dieting efforts. It’s not uncommon to hear people refer to ‘wanting to lose weight’ or needing to ‘drop a few pounds’. Regardless of what the exact words are, the point is always some sort of reduction in ‘weight’.
Fitness competitors and bodybuilders tend to speak more of ‘fat loss’ or reducing ‘bodyfat’ levels.
Reducing body fat levels will also result in weight loss, but to a bodybuilder there is a distinct difference, and that is the understanding that there is also a certain amount of ‘water weight’ that also must be dropped to get ready for a show.
In both cases overall body weight will be reduced (either from a reduction in body fat or body water).
When you embark on a weight loss program you will likely lose both body water and body fat. There is no need to make a distinction between the two as it is advantageous to both your health and your overall look to reduce both.
It’s not possible or practical to try and divide fat loss from weight loss, and it’s not worth your effort or attention.
Focusing on a reduced calorie diet will take care of both and get you to where you want to go.