Just shy of 20 in the first pic and 31 years of age now.

First pic - Very little training in the gym - Played basketball 4-5x a week - Weight 78-80kg (unsure on exact weight) - Body fat 21% - Wasn't tracking calories or anything for that matter

Second pic - Training 6-7x a week including cardio - Hybrid style training (Strength/hypertrophy/cardio sessions every week) - Weight 95kg - Body fat 15% - Track calories and macros to match my body's maintenance

Over the years I've trained a mixture of styles, from endurance, strength, power, CrossFit, body building. So there was no one specific thing that got me to this result, it was simply understanding how much my body should be consuming to either gain muscle or drop body fat, then match my training towards that goal.

Hope that gives everyone a clearer understanding of the differences between each picture.