A relationship DNA test, also known as a paternity test or a DNA parentage test, is a type of genetic test used to determine the biological relationship between individuals. The most common use of a relationship DNA test is to establish paternity, but it can also be used to determine other familial relationships such as maternity, siblinghood, or grandparentage. It's important to note that relationship DNA tests have a high degree of accuracy, often exceeding 99.99% for conclusive results in paternity cases.