what is the importance of economic in islamic countries
Islamic economics has some very clear cut rules and a built in welfare system, as giving money to the needy is a big part of the system. Another well known aspect of Islamic economics is the belief that paying interest on loans and capital is wrong (a belief that also existed in medieval Christian Europe, for example, so it is not only Islamic). This avoids many abuses, but in the modern world is hard to sustain. You can get an overview of this topic here.