Am I still getting stronger?

Now, I've heard that lifting heavier weights with less reps will build muscle m, whereas lifting smaller weights with higher reps will add definition. For the past year I've been using the first method to get stronger and it's worked wonderfully. Now that I can't get to the gym anymore, and I have only up to 12lb dumbbells to work with at home, I need to find another way of training. I know that using the smaller weights will add more definition, but is that all? Will I still be getting stronger?