Whats the difference between a rhombus and a parallelogram?

You can't exactly say that there's a 'difference', because a rhombus is just

a special kind of parallelogram ... one whose sides are all equal. So every

rhombus IS a parallelogram.

Rhombus is a quadrilateral with four congruent sides

Parallelogram is a quadrilateral with four parallel sides, two by two