Separating and restricting the movement of people exposed (or potentially exposed) to a contagious disease. They would need to quarantine even if they do not have symptoms.
Those who have come into contact with a person who has developed COVID-19 disease, need to self-quarantine. Some countries have imposed fines and even jail terms for those not abiding by quarantine rules (usually an instruction to stay at home for a period of 14 days).
Although rare in modern history, quarantines were fairly common in ancient times, before medicine stopped the spread of infectious diseases. The word quarantine comes from the Italian words quarantenara and quaranta giorni, or 40 days, the period of time that the city of Venice forced ship passengers and cargo to wait before landing in the 14th and 15th centuries to try to stave off the plague. Quarantines have often generated tensions between protecting public health versus respecting individual rights.
TIP: Quarantine is different from isolation and cannot be used interchangeably
Infectious Disease Prevention