When I was growing up, you either went to the gym to 'bulk up' or 'go for tone'. You used heavy weights at low reps to bulk. Light weights with higher reps were for 'tone'.
It's still common to hear talk about which exercises are better for bulking vs toning, but we now know that's not the question. The question is - how should you train in order to perform, look, and feel the way you want to feel?
Aesthetics: Aesthetics training is about image. The goal is to shape each muscle group with isolation and hypertrophy emphasis. High protein, low carbohydrate diets are needed to achieve low levels of body fat so the muscle forms can be visible. Performance drops as body fat get lower because the body gives up its energy reserves in exchange for more definition. Pro - you look good. Con - you feel terrible and get winded walking up stairs.
Strength: Strength training is about maximizing power output. Period. Powerlifters and Strongman competitors don't care about how individual trapezius muscles lay in relation to the lateral deltoids - they care only about how much weight they can put overhead.
Performance: Powerlifters are strong, bodybuilders look 'big'. Performance athletes train to operate with strength and speed at intensity. Performance athletes trade raw strength in exchange for work capacity over longer periods of time. Performance athletes also trade aesthetics for a more functional physique. Higher body fat percentages are needed in exchange for more energy and better performance.
The question of bulking vs toning doesn't address the main concern which is - how do you want to live? I find that bulking vs toning is a small concept compared to the real question: what do you value about movement, food, athletics, and health?