A minor is a person who is under the age of majority in his or her jurisdiction. The age of majority may or may not be the same as the age of consent. Usually it's higher at 18 where the AoC is 16.
The child liberation movement works to give minors increased rights. The movement sees the illegality of sexual relations with and between youth as only part of a larger injustice toward them. Activists endeavor to give minors rights such as voting in addition to the right to decide over their own bodies.