Birth control is a way to prevent pregnancy. While there are many different types of birth control, they all fall into two different categories: barrier or hormonal.

Barrier methods block the sperm from getting to the egg. Condoms (both male and female), diaphragms, and cervical caps are all barrier methods of birth control.

Hormonal methods basically change the menstrual and ovulation cycle to prevent a female from releasing an egg from her ovaries, known as ovulation. That makes it nearly impossible for a pregnancy to happen, since there is no egg present to join with the sperm. Birth control pills ("the Pill"), Depo-Provera ("the Shot"), NuvaRing ("the Ring"), and Ortho Evra ("the patch") are all hormonal methods of birth control.

For more information and photos of  all the birth control methods, go to the story "An A to Z of Contraception" by Claire Marchetta, 18, Staff Writer.