These beautiful Bromeliad plants use their specialized roots to cling to tree trunks and branches taking nothing but support from trees; drawing their water and nutrients from air and moisture that accumulates between their leaves like tiny little cups, storing water for later.

Commensalism Mutualism Parasitism Predation
Which one

The relationship described between the Bromeliad plants and the trees is commensalism. Commensalism is a symbiotic relationship where one organism benefits (the Bromeliad plants, in this case) while the other organism (the trees) is neither harmed nor benefited. In this case, the trees provide support for the Bromeliads, but the Bromeliads do not harm or benefit the trees in return.