I'm an azn, I know math. So, look:
- operation x/0 is not defined (when x not 0)
- operation 0/0 is indeterminate
What does it mean "not defined"? In simple words: you can drive your car but you can not fly with it. Operation "flying" is not defined for your car. It is the same as with division. Not defined. You can not even try it.
What does it mean "indeterminate"? tl;dr Look up on wikipedia (Indeterminate form).