Traditional birth control methods

Celibacy or sexual abstinence - this means avoiding penis-in-vagina intercourse to prevent pregnancy.
Withdrawal (coitus interruptus) - when the man is about to have an orgasm he pulls his penis out of the vagina. The ejaculation occurs outside of the vagina. The idea behind this method is that no sperm will be deposited in the vagina. According to some organizations this method is about 90% effective if used correctly. Typically, though, about one third of couples who use this method will experience an accidental pregnancy within twelve months.
Modern birth control methods
Male condom - this device is a mechanical barrier which prevents pregnancy by stopping sperm from entering the vagina. It should be placed over the penis before sexual intercourse begins. They are made of polyurethane or latex. Male condoms look like long thin deflated balloons. As well as preventing pregnancy, they are also useful in helping protect sexual partners from sexually transmitted infections (STIs).
Female condom - made of polyurethane. The female condom has a flexible ring at each end - one secures behind the pubic bone to hold the condom in place, while the other ring stays outside the vagina.
Spermicides - may be placed in the vagina before intercourse and create a chemical barrier. Spermicides may be used alone, or in combination with a physical barrier.
Contraceptive sponge - The contraceptive sponge has a depression to hold it in place over the cervix. Foam is placed into the vagina using an applicator. As well as having a spermicidal which destroys the male sperm, the sponge also acts as a barrier which stops the sperm from reaching the egg.