Quarantine and Isolation usually lasts between 14 days and 60 days depending on the virus or disease that the person or people are being quarantined for.
For viruses such as the Coronavirus people are typically quarantined for around 14 days which is about the time that the person recovers from the Coronavirus.
However it can sometimes last longer.
Being in quarantine means to be isolated in a room, house etc away from other people so that you do not spread the disease to other people.
Some people who have diseases will be quarantined for either 14 days to 60 days depending on how severe the disease is.
For people who have the Coronavirus they are being quarantined for around 14 days and some people are self quarantined while others are being forced into quarantine.
It's basically just means that the people who are infected with a virus or disease is isolated and kept away from other people who do not have the virus or disease.