It does mean you share some amount of autosomal DNA with them that you both inherited from a common ancestor, but it doesn't tell you whether it is 100 years or 300 years ago. The prediction that it is in the 4th cousin level has not been very reliable, but you are related in some fashion. The best way to use the product is to develop your own family tree out at least four or five generations, then start looking for common surnames, locations etc...almost the way you would if you were doing paper research, but the dna results point you in the right direction to look. It does require that you do some old fashion genealogical research to use the dna results best. However, ancestry.com only shows you ten generations of common surnames..beyond that you have to hunt for yourself in matching trees.