A preteen or pre teenager is a person between the ages of 9 years old to 12 years old.
A teenager is someone between the ages of 13 to 20.
Once the age has no teen in the numbers then the person is no longer a teenager although 18 is also considered an adult.
However you're not fully an adult until 21 years of age.
While known as preadolescent in psychology, the terms preteen, preteenager, or tween are common in everyday use.
A preteen or preteenager is a person 12 and under.
Generally, the term is restricted to those close to reaching age 13, especially ages 9 to 12.
A teenager, or teen, is someone who is between 13 and 19 years old.
They are called teenagers because their age number ends with "teen".
The word "teenager" is often associated with adolescence.
Most neurologists consider the brain still developing into the persons early, or mid-20s.
Brain Maturity Extends Well Beyond Teen Years Under most laws, young people are recognized as adults at age 18.
But emerging science about brain development suggests that most people don't reach full maturity until the age 25.
Good judgment isn't something they can excel in, at least not yet.
The rational part of a teen's brain isn't fully developed and won't be until age 25 or so.
In fact, recent research has found that adult and teen brains work differently.
Adults think with the prefrontal cortex, the brain's rational part.