Joseph Stalin was the leader of the Soviet Union from 1929 to 1953. Although he had succeeded in establishing communist governments in all of Eastern Europe, he wanted to increase his control over each individual state. For this reason, he founded Cominform (Communist Information Bureau) in the year 1947 with the purpose of bringing together the European communist parties and coordinate their actions under the guidance of the Soviet. The roles of Cominform included publishing propaganda that enhanced the solidarity of communist parties internationally. It was dissolved in 1956. Comecon (Council of Mutual Economic Assistance), on the other hand, was established in 1949 to specifically coordinate the economic matters of member states including economic policies that govern multilateral trade among member states.
Stalin established both of these groups for the same reason. They were both meant to strengthen the communist bloc and to strengthen Soviet control of that bloc.
After World War II, the Soviet Union established a communist bloc made up of satellite countries in Eastern Europe. Stalin wanted to have more control over these countries. He wanted to control them so that the Soviet Union could direct the spread of communism and so they could serve as a reliable buffer against the West. In order to gain more power over these countries and to make them stronger as a bloc, he established Cominform to increase Soviet political control and Comecon to increase Soviet economic control.