You asked the same question on Monday!
Endler's livebearer is Poecilia wingei and a guppy is Poecilia reticulata, both are in the same genus but they are different species and will cross breed with each other.
What are your plans for either species? If just using for feeding other fish it won't matter. If you are looking to breed for sale, choose one or the other and verify your source for the fish.