Liquid solutions are the most familiar type. A liquid solution can contain components that would by themselves be gases, liquids or solids. A water solution might contain some dissolved air, some alcohol and some dissolved salt. If the concentration of one component is much greater than the others, that component is referred to as the solvent, the others are referred to as solutes. A single substance can contain more than one type of particle.
Water also consists of transient structures involving large numbers of molecules.
Yet there is only one component.