Certain decisions that businesses make are called risks because the decision they are making could be very risky and could lose a lot. For example if you are a businessman and your making an investment in a upcoming company you are making a risk by investing because the company could be a flop. But also the company could be a great success. That is how it is a risk you never know how it will end
The Abbasid dynasty ruled as caliphs from their capital in Baghdad, in modern Iraq, after taking over authority of the Muslim empire from the Umayyads in 750 CE.