Temperature is a mearure of microscopic motion. A gas close to absolute zero temperature consists of almost immobile particles. It condenses, in a sense like atmospheric moisture in a room at the window-pane or at dust particles.

The distinction: at a billionth part of a degree the particles condense mutually, in a way; they do no longer need an interface or condensation nuclei for it - and they do it for quantum mechanical reasons. The figure shows a simulation where more and more particles accumulate near the state of rest.

Bose-Einstein-Condensates, as these coldest gases of the universe are coined, are artificial products. The space, at about 2.73 degrees, is much too warm so as to allow them to freely exist.