Aerosols are liquids dispersed in a gas, sols are solids in liquids, emulsions are liquids dispersed in liquids (more specifically a dispersion of two immiscible liquids), and gels are liquids dispersed in solids.
Aerosols are liquid particles suspended in a gas, sols are solid particles in liquids, emulsions are liquid droplets dispersed within other liquids (specifically a dispersion of two immiscible liquids), and gels are liquid components embedded within solids.