What does a cap rate of 7.9% tell you about a duplex?

[Matt Bailey]

What does a cap rate of 7.9% tell you about a duplex?

How do you use this information?

thank you 

[Ralph Justiz]

The net income the property produces annually is 7.9% of the purchase price.

I.E. if the purchase price is 100K, the property produces 7,900 dollars every year after expenses are paid for.