Most people are definitively male or female, but with these genetic conditions that doesn't always fit. As one example - androgen insensitivity. A person with XY chromosomes, but their cells don't respond to male hormones. Depending on the degree of insensitivity they can develop as male with minor feminine features, female with no masculine features, and the entire spectrum in between, but all with typical male testosterone levels. That spectrum doesn't fit into strict male/female definitions and where the line is drawn clearly gets subjective and pretty messy.