Contraceptives are primarily for birth control. This day and age with so many choices in contraception systems and methods, having unwanted children are a rarity. Lack of education would be the primary source of this issue and not a lack of means to stop from conceiving.
Contraceptives have also become essential in the fight of the spread of sexually transmitted diseases (STDs). Condoms are effective in this arena.
The most popular types of contraception are: birth control pills, male condoms, intra-uterine systems (for instance the coil or mirena), contraceptive injections, birth control skin patch, diaphragm. Other methods of contraception include vasectomy, the withdrawal method, and the rhythm method.
The question that bothers most people looking for contraceptives is its effectiveness. You will not find a medical claim or even just a plain claim that say any of these are 100% effective. The truth is, nothing works as well as complete abstinence from sex.