Also known as Council of Mutual Economic Assistance (or just remember it was COMmunist ECONomy)
This united the economies of Eastern Europe with the Soviet Union. Meant to be their version of the Marshall Plan where the USSR would provide investment and share technological knowledge with the Eastern European states.
However, USSR’s post-war economic recovery was slow and they could not provide economic aid of similar scale as the Marshall Plan.
Arrangements mostly only benefited USSR.