While bodybuilders and strength trainers use the same tools in the gym, they approach their workouts differently. For one, their goals are distinct: optimizing muscle size vs. strength – they aren’t the same!
Strength athletes like powerlifters focus their workouts around a basic movement (like the bench press, squat or deadlift) that’s done very heavy for fewer reps (lower volume) and significantly longer rest periods for both better muscle and central nervous system recovery. Bodybuilders create workouts around individual muscle groups, like chest or legs, with moderate weights and volume and just 60 to 90 seconds between sets (good enough for significant muscle recovery, but not long enough for CNS recovery).
What’s more, powerlifters complete their workouts by choosing secondary exercises that help them strengthen their main lift (say, bench press), whereas bodybuilders choose exercises that work the target musculature from different angles to build the most fully developed muscle possible.
Don’t think that you have to choose one style or another exclusively. Many lifters use elements of the others’ training systems at different times to prevent stagnation and promote better long-term gains.
Don’t forget that both styles of training also require big-time commitment to eating and supplementation!