For example, women have XX and men have XY.
Intersex conditions are actually quite common and they are not always easy to identify. Actually, most times intersex conditions are invisible. It so happens that many men with XX / XYY chromosomes and many women with XY chromosomes never find out they are intersex, unless they sequence their DNA. They might have invisible conditions.
A person who is intersex (the politically correct term for hermaphrodite) is a person who has both male and female genitalia, and they could have any chromosomal combinations. One type of person who is intersex is a chimera - this person might have had another sibling in the womb, who wasn’t strong enough to survive gestation, and they absorbed it or they absorbed parts of it. An intersex person doesn’t need to be a chimera necessarily, they can simply have a different hormonal makeup that results in both sets of genitals to develop up to certain stages. However, we don’t know of any recorded intersex (human, not animal) that has both sets of genitalia functional.