The term "abortion" actually refers to any premature expulsion of a human fetus, whether naturally spontaneous, as in a miscarriage, or artificially induced, as in a surgical or chemical abortion. Today, the most common usage of the term "abortion" applies to artificially induced abortion.
The vast majority of all abortions performed today are done for social, not medical reasons -- because a woman doesn't feel ready for a baby at the time, because her partner wants her to have an abortion, etc.
When it comes to an issue like abortion, there will always be opposing beliefs. These contrasting views are categorised into the pro-life view and the pro-choice view.
*To most pro-lifers, human personhood begins at the instant of conception. Thus, they view each abortion as a form of murder. They note that at conception, a human life with its own unique DNA comes into being. They feel that all elective abortions should be prohibited; some feel that all abortions -- no matter what the justification -- should be criminalized.
*To pro-choicers, human personhood begins later in gestation or at birth. Pro-choicers view abortion at any time before personhood as a decision that should be left up to an informed woman.
Abortion is a choice that women, all around the world, have incurred, however, it is very apparent in the lives of pregnant teenagers, university students and young women who want to establish a career before starting a family. I myself am a pro-choice even though I believe I would never bring myself to have an abortion. The rights of women should come before arguing whether abortion is morally or legally right.