Two things are needed to make a baby: a sperm cell and an egg cell. A man makes the sperm cell inside his body and a woman makes the egg cell inside her body.
Both the sperm cell and egg cell are very small. You would need a microscope to see them in real life. A microscope is like a magnifying glass, only much stronger.
When the sperm cell and the egg cell meet each other, they make a tiny baby that’s smaller than a grain of salt. The baby will grow inside a special place in woman’s body called the uterus. After about nine months, the baby will come out as a little boy or girl.Unsupported extension