If you have ever wondered what a half-cousin is, you have come to the right place. It should be noted here that Half-first cousins are two people who share one grandparent instead of full cousins who share two grandparents. This happens when the parents of the two half-cousins are half-siblings. Here, the half-cousin chart is a visual explanation of how half-cousins occur in families. As we see, the grandfather had two marriages. He had one son with each wife, and those sons are half-siblings. Each son had a child, and those children are half-first cousins. You can create similar cousin charts using EdrawMax Online.