Question: Most forums cite minor differences in speed, backup, etc.
It's about time someone tell how the two differ when it comes to GUI data validation.
Do this 2 Database always depend on java(or other software), or do they have the ability to create a user interface the accepts only valid input. Things like: positive numbers only, age between 1 to 100 only, email must be correct. I would be scared if my software accepts 500 years old for age.

Answer: 
You are probably referring to Java Generics:

<http://www.oracle.com/technetwork/java/javase/generics-tutorial-159168.pdf>
This is [parametric polymorphism](http://en.wikipedia.org/wiki/Type_polymorphism#Parametric_polymorphism), another important form of polymorphism other than subtyping.

In Java land, they call it [Generics](http://www.oracle.com/technetwork/java/javase/generics-tutorial-159168.pdf) (see also [Lesson: Generics](http://docs.oracle.com/javase/tutorial/extra/generics/index.html)).