New to Java

Okay, I have got pretty good at understanding Static Classes, Methods, and Variables as well as Instance, etc.

But, when it comes to import and extend, I still don't understand the difference and when to use either. Yes, you import a API for the Java Library, but you can extend the functionality of a Super/Abstract class into a sub class. But the super clase could be a API from the library, right? Wrong? So do I import or extends. Man, I am confused on this particular subject. Help!!

signed
Java-Gotta-B!