Z-Index Relative or Absolute?

Question

I\'m trying to find an answer to the following question:

Is an element\'s z-index style its absolute stack order, or its stack order relative to its parent?

Answer 1

For example:

  






this class is relative
this class is fixed


x3: this class is relative
x4: this class is relative
x5: this class is relative
x6: this class is relative
x3: this class is relative