You are not alone in vague understanding! And it is easy to see why. The EU is built like the brain, with massive redundancy - a linear process it is not. Not many people can get their heads around the fact that there exist 'The Council of the European Union', 'The Council of Europe' and 'The European Council'. Quite an Alice of Wonderland arrangement. 3 different bodies and only one legally part of the EU.

You can't be me, I'm taken