How many 5 gallon buckets are in a yard of dirt?

Excuse me, I was wondering if you could clarify something for me. The paragraph mentions "How many 5 gallon buckets are in a yard of dirt?" and I'm a bit confused. Is there a standard conversion rate or does it depend on the type of dirt and its density? I'm trying to plan a landscaping project and need to know how much dirt I'll need to buy. Can you please explain how I can calculate this or provide an approximate number? Thank you in advance for your help.