Cars extended the range of dating as well as enabled back-seat sexual exploration.
In the mid-twentieth century, the advent of birth control as well as safer procedures for abortion changed the equation considerably, and there was less pressure to marry as a means for satisfying sexual urges.
In the twentieth century, dating was sometimes seen as a precursor to marriage but it could also be considered as an end-in-itself, that is, an informal social activity akin to friendship.
Dating may also involve two or more people who have already decided that they share romantic or sexual feelings toward each other.
Dating as an institution is a relatively recent phenomenon which has mainly emerged in the last few centuries.