isolation: the separation of a person (or animal) who is ill from healthy people (or animals), to prevent the spread of disease

quarantine: the separation from other people (or animals) of a person (or animal) who has potentially been exposed to a communicable disease, to prevent the spread of disease. Importantly, the individual in quarantine does not yet have any signs or symptoms of the disease – that is, they are not currently ill with that disease. The word quarantine relates to the Italian word for forty – during the Black Plague in 14th-century Europe; ships were required to wait for 40 days before their passengers could come ashore. The period of quarantine differs for different diseases. Quarantine can also be applied to plants or objects such as vehicles