When would I use it? 

You would use bodybuilding if you have a goal of wanting to overhaul your physique and transform the way your body looks. 

What does it involve? 

Bodybuilding is its own sport, you compete to look the best on stage, instead of lifting the most weight (like powerlifting or weightlifting). Bodybuilding typically involves strict dietary guidelines too, the food you eat outside of the gym is a vital component of the sport. The aim is to develop muscle mass, and change the composition of your body, not necessarily to develop strength – however, this will also happen when engaging in bodybuilding training. 

How do I get involved? 

Again, it's good to have a coach or personal trainer help guide you into bodybuilding. This said you can start out by picking up magazines like Women's health/ Men's health, or following bodybuilding websites or bodybuilders on Instagram.  If you want to head to the gym you can workout on your own and use weight machines to get you started, however,  for many can feel quite boring and can turn you off going to the gym.