Pro-life is the name given to people or organisations that oppose abortion, or the woman's right to choose, under some or all circumstances.
The name comes from the belief that life begins at the moment of conception, and that removal of the embryo (1-8 cell stage) or fetus (8-fully developed organism) is equivalent to the murder of a person at any time after birth.
Currently, America has legal abortions available to those who want and can afford them. Persons of the pro-life platform wish for abortion to be illegal.
Often called Anti-Choice.