I know what a deductible is. But what is the term "20% coinsurance after hospital deductible"

What is 20% coinsurance mean??

Also it mentions"20% coinsurance up to a out of pocket maximum per contracted year of $1,500.00

Take the total bill, pay the deductible, then you pay 20% of the balance.
Say bill is 1,000 and deductible is 200 (you pay 200)
You then pay 20% of 800 dollars or 160 dollars and insur. co. pays 640 dollars.
Your total paid is 360 dollars. Insur. 640