When more doesn't mean more

Some people I know have this misconception that the more they lift, the more they will grow, the stronger they become. The amounts of repetitions does not directly relate to the amount of growth or even strength. As science goes, strength is measure by the amount of weight that you are able to lift. As a comparison, if I could lift a 1kg weight for a 200 times doesn't mean I am stronger than another dude who manages to lift 200kg even thought the maths is the same (1x200 = 200x1). The latter is certainly more impressive, and for a good reason.

Strength training require lifting weights, what kind will depend on your current strength. Pick a weight which you are able to lift for 8-10 reps at a single set. Do about 3 sets, with a minute rest in between. You will become stronger. Picking an easy weight and lifting it countless times will do little to increase your strength. It could help with muscle endurance though, but that is for another time.

It is the same story with bulking up. You will need weights. Weights that should increase periodically throughout your training. This is because you will gain strength, and you'll have to increase your weights again, to match up with your strength. However do note that this is a rough explanation, as there are much more science and factors that are involved. Just imagine this as a graph, you may think it would be linear (straight), but things don't usually work that way.