In this short review paper, two definitions of ice slurry are presented. Furthermore, ice slurry systems and the most relevant components of ice slurry systems are described. Such equipment are ice slurry generators (different physical principles), storage tanks, mixing elements, pumps, piping systems, consumers, e.g. display cabinets in supermarkets, etc. The direct contact ice slurry generator is an efficient low-cost machine, which at present is experimentally and theoretically investigated. A nearly complete list of the advantages and disadvantages of ice slurry systems in comparison with direct expansion systems is given. Advantages to the environment, where ice slurry technology is applied, are addressed. Furthermore, the article lists existing and possible future applications of ice slurry technology.