A teenage horoscope is unique because it uses the planets to give insight into a specific age group, dealing only with what is most important to these particular individuals.
Believe it or not, the concept of a teenager is a very modern one. Up until the later part of the 20th Century, boys and girls went right from childhood into adulthood with a puberty ritual and no middle ground. The teenager concept was invented to give the children of so-called 'more advanced' societies a grace period to develop between child- and adulthood instead of a one-day transformation with a ritual.
The "teenage years," quickly became a time for soul searching, exploring, and finding one's self independent of the family structure. In general, teenagers have become independent beyond the childhood need for constant parental supervision, but they still do not possess the full skill- and mindsets needed to function effectively in an adult society. Because they are caught in between, teenagers are generally more self-conscious than any other age group.
Insight into where a teenager fits into social groups and the approval of peers are other important aspects of a Teen Horoscope. But probably the number-one issue explored in a teen horoscope is love and sex, since the teenage years involve sexual exploration and maturing.
Teen horoscopes give insight into these very specific issues, since the areas detailed are of the most concern to this age group. In general, becoming aware of one's self is the primary function of the teenage years and teen horoscopes are a fun and effective way to gain this insight.