What does it mean for a non generic class to extend a generic class

Question

public class B extends C  {

}

What does this mean? That C needs to extend A? What extra restriction am I putting instead of just saying B ext

Answer 1

public class B extends C  {

}

1. If A is undefined there is no restriction on B( can be any the of Object Class).
2. If the Type of A is defined,then B must be of type A or a Subclass of A.