Chemistry Sets are comprehensive collections of chemicals and apparatus designed for a broad overview of chemistry; chemistry kits are more focussed on some limited but educational or entertaining chemical phenomena.
Chemistry, a branch of physical science, is the study of the composition, properties and behavior of matter. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds. Chemistry is also concerned with the interactions between atoms (or groups of atoms) and various forms of energy (e.g. photochemical reactions, changes in phases of matter, separation of mixtures, properties of polymers, etc.).