Saturated aliphatic fused rings refer to a class of organic compounds that consist of two or more aliphatic (non-aromatic) hydrocarbon rings that are fused together, where each carbon atom in the ring is fully bonded to hydrogen atoms, and the structure does not contain any double or triple bonds. These compounds are "saturated" because they do not have any unsaturated bonds, meaning all of the carbon-carbon bonds in the rings are single bonds. Fused rings refer to the shared bonds between the rings in the molecule.