Yes. Basically, both work similar but an MLM is an actual business while a pyramid scheme just fakes to be one.
Take Tupperware for instance. Independent of its structure as a customer you get a real product / service. There is an actual transaction between a customer and a company (reseller). A customer does not need to be part of the MLM.
In a pyramid scheme the money comes directly and only from its participants. It just redistributes it. As long as the scheme grows this works until it eventually collapses.