Comment by ADRIANFR

The difference between socialism and communism was all in the "communist" propaganda. All east-european countries were "socialist" with the almost utopian goal of becoming "communist". It's a label that could be changed at anytime by the leaders. Technically, according to the doctrine, socialism was "everybody contributes based on ability, and receives based on the contribution", while communism was: "everybody contributes based on ability, and receives based on their needs", which was utopian. Western countries did not (want to) grasp the difference, so they just called the eastern block "communist".