Preparing Gaussian Kernels

[Gregory Lahman]

Hi, I was wondering if someone can explain to me the difference between multiplying 2 GP's together and adding them? The scalismo videos on future learn didn't really make sense to me when it talked about them. For example, would a GP with l=100 and s= 25 multiplied by a GP with l=5 and s=10 give you both large and small deformations or is it best to  use addition of GPs for that purpose?