To be considered truly Green, a product must go through rigorous testing and receive Green Seal Certification.
Green is an unregulated term however, and is frequently used by products that are not actually certifiably green (Simple Green is a great example of this.)
So what does green actually mean? To be certified Green, a product must prove through testing to be better for Human Health and the Environment. Typically Green Products are in fact chemicals, they are simply safer than traditional chemicals.
Natural Products are just that, natural. Their ingredients are naturally occurring and include elements such as baking soda, natural soap, vinegar, lemon juice, salt, borax, essential plant oils, and natural oils such as olive and jojoba. Most natural products are safe to consume (not that you would want to,) and thereby have little to no health or environmental impact.