What is a square a parallelogram but a parallelogram not a square a square

A square has both parallel sides
being the top and bottom
but also both the sides 

AND so does a PARALLELogram
BUT a square has ALL right (90 d) angles 
and a parallelogram does NOT 

ALSO . . . . . SUMMARY . . . . .  
The sides of a square are parallel
and all the angles equal 360 degrees,
so it's a parallelogram. BUT a
parallelogram is NOT a square
because a squares angles need to be 90 degrees.

does that answer your question?

Square is 90 degrees but parallelogram is not