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 really how babies are made.
You might know that the human body is made of millions of millions of tiny, microscopic biological cells. These cells all work together to keep us alive and able to do things. Well, some of these cells are for reproduction. These cells are called gametes. Men have the male gamete, which is called sperm, and women have the female gamete, called an egg or ovum. When these two tiny cells meet they combine and start to form a new baby.
Here's how that works in practice.
A man and a woman, who hopefully love each other very much and are married, have sex. That is, the man puts his erect penis into the vagina of the woman. The sexual pleasure causes a man to have an orgasm and ejaculate? semen into the woman's vagina. Ejaculate means the semen is suddenly sprayed out of the penis. The semen is filled with many millions of sperm cells (the male gamete), most of which will try to get into a woman's egg.
The sperm travel up the woman's vagina, through the cervix?, into the uterus, and usually up the Fallopian tubes, to try to find an egg (the female gamete). This isn't like a regular chicken egg, it's a tiny biological cell almost too small to see. If the sperm find an egg they will try to get into the egg, and one eventually will. As soon as a sperm enters the egg the egg changes rapidly, and divides into smaller and smaller cells. This is where a human life starts.
If a sperm has entered an egg it is called a fertilised egg or zygote?. The zygote will travel down the Fallopian tubes and try to attach to the wall of the uterus. This is called pregnancy (or maybe pregnancy is when the egg is fertilised is in the woman). For nine 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 through vagina, in this way 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.