In the natural order of things, women produce eggs, which are fertilized by sperm from the man. This combined cellular material becomes a fetus and, eventually, emerges to take its place in the world as a human being with every right and privilege afforded such a being. There are situations where people decide that the above process is not desirable, inconvenient, or potentially harmful. They use their intellect to discover methods by which the natural progression from egg and sperm to new human being is blocked or prevented.
Some people understand the cycles when a woman is likely to conceive if she engages in sexual union. They avoid sexual intercourse during those times when fertility is highest. This is referred to as the rhythm or natural birth control method.
Some couples can turn to physical means to prevent pregnancy. One approach would be a condom – a device worn by the man that prevents the sperm from reaching the fertile egg. Another is a diaphragm – worn by the woman with the same intentions as the condom.
Others rely on drugs that mimic human hormones to interfere with the natural cycle that release fertile eggs. These approaches are the birth control pill and the birth control patch. There are many versions, but each works by chemically interrupting the implantation of a fertilized egg into the mother’s womb. No implantation means no pregnancy. There are also devices called IUDs (Intrauterine Devices) that can be inserted in the woman that also prevents a fertilized egg from implanting.
A final approach to preventing pregnancy is surgical. Men and women can each have themselves surgically altered to prevent pregnancy. These procedures are usually not reversible.