Reproduction
Reproduction, or procreation, is where babies come from. That is, it's how people make more people. Sexual? reproduction is pretty weird, but it's a biological reality.
A man? and a woman, who ideally love each other romantically and are married, have sex. That is, the man puts his erect penis into the vagina of a woman. The sexual pleasure causes a man to have an orgasm and ejaculate? semen into the woman's vagina. The semen is filled with sperm who travel there from the epididymis? (inside the scrotum) through the ductus deferens? (old term "vas deferens"). A sperm is a reproductive cell, or gamete, of the male.
The sperm travel up the vagina, through the cervix?, into the uterus, and usually up the Fallopian tubes to meet an egg. The egg is the female reproductive cell, or gamete?. This isn't like a regular chicken egg, it's a tiny biological cell almost too small to see. Millions of sperm try to get into the egg, and one eventually does. As soon as a sperm enters the egg the egg begins to change rapidly, and divides into smaller and smaller cells. This is where a human life starts.
Later, the egg attaches to the wall of the uterus. This is called pregnancy (or maybe pregnancy is when the egg is fertilised is in the woman). For 9 months the baby grows in complexity and size. Then the mother gives birth? to the baby, which travels out of the uterus, through the cervix, and out the vagina, thus getting out of the woman's body. (Some babies are born through Caesarean section?.) This is how you and I and everyone else came into the world.
What a deal, eh? Good job reading it. Congratulations, you now know where babies come from.