A cubic yard is a 3' x 3' x 3' cube. That is close to about 7 wheelbarrows of most products.
If you are comparing to bagged mulches, most of those are 2 cubic foot bags, so a yard would be equal to 13.5 bags of mulch.
If you have any questions you don't see answered here, or need a quote on bulk material delivery, please call the office at (704) 253-7010