Sometimes when a baby is born, their body is not exactly like a boy or a girl. This can happen because of things that went wrong when the baby was growing inside their mom's tummy. We call this "disorders of sex development", or DSD for short.
DSD is when some parts of a baby's body that make them a boy or a girl don't work like they're supposed to. For example, a baby might have a penis but also have ovaries instead of testicles. Or they might have a vagina but also have testicles instead of ovaries.
People with DSD are usually still able to grow up and do all the things that other kids can do. They might just need a little extra help from doctors and other experts to take care of their body and stay healthy.
It's important to remember that people with DSD are just as special, important, and loved as everyone else. And no matter what their body looks like, they deserve to be treated with kindness and respect.