Duration differ from capacity in a way that: Duration is a measure of time, while capacity is a measure of quantity.
For example, let's say that you own a storage that you use for your food packaging a company. The storage managed to contain 10,000 packages and it can be filled up within 10 hours of operation. In this case, 10 hours is what considered to be the duration while 10,000 packages is what considered to be capacity.