unions

Tankies, self described communists, I wasn't sure what word to describe the various types of socialists I have seen claim ownership of unions.

Understood. In a perhaps ironic way of stating it, unions do not belong to socialists or communists, they belong to the workers. It is possible to be right-wing and support unions but, as right-wing policies are consistently anti-labor, this inevitably leads to a "leopards ate my face" situation.

I think it's also a good idea to thoroughly understand what one opposes or supports. Tankie is a pejorative that originally was used by a set of British Marxist-Leninists to describe Marxist-Leninists who were hard-line supporters of the USSR's use of force (tanks) to quell revolt. Not all self-described communists are even Marxist-Leninists. There's anarcho-communists, maoists, non-Marxist communists, and so on.

Socialism and communism are also separate, but similar structures. One of the differences being that socialism tends to aim for collective ownership of the means of production, whereas communism tends to also aim for collective ownership of distribution and consumption. Another way to look at it is that socialism tends to be organized in a manner that is meritocratic (everyone starts with the same economic opportunities, without hereditary wealth, and receives back according to their contribution) whereas communism intends to be more altruistic, distributing the fruits of labor principally based upon needs. Some communists would argue that socialism is a step towards communism but not all socialists would agree.