Made of relations — where the connections are the structure, not decoration on it.
Built on relation, from Latin relatio (a bringing back), from referre: re- (back) + ferre (to carry); a relational structure is one where the carrying-back between parts is itself the structure, not a decoration added on top of it.
Made of relations, where the connections are the structure rather than something laid over it. The root's carrying-back is the whole architecture, not an afterthought to it.