Designed to prevent a second peak, the system is less strict than full lockdown but requires ongoing cooperation from everyone.
Health secretary Jeane Freeman said: “What’s new is that now, as we begin to ease some of the lockdown measures, in order to keep the virus suppressed, we will also need to trace your close contacts and advise them to isolate for 14 days, with support.
“So if you get a positive test result you will be asked who you have been in close contact with. This includes people in your household, people you have had direct face to face contact with for any length of time, and those you have been within two metres of for 15 minutes or more.
“This NHS system is entirely confidential, when the people you have been near are contacted they will not be told who it is that they have been in contact with. This information is only collected and used by NHS Scotland for the purposes of tracing your contacts. The Scottish Government will not have access to it.
“If you receive a call or a message from a contact tracer to say you have been in contact with someone who has tested positive, they will ask you to self-isolate immediately. It is hugely important you do this in order to stop the spread of the virus.
It is only by all playing our part, getting tested, providing information and agreeing to isolate, that we can cut the numbers of people getting the virus.”
As before, anyone with symptoms of the virus, such as continuous coughing, high temperature or altered senses of taste or smell should contact NHS Inform online or call 0800 028 2816 as soon as possible.
Contacting the NHS will lead to booking a test at a mobile unit or a drive-through centre, or possibly having a home testing kit sent out. While waiting for the result, everyone in the household will have to self-isolate.
If the test then turns out to be positive the person with symptoms will need to remain in isolation for a week and other members of the household for two weeks.
There is information on the Scottish Government website about self-isolation, including advice on caring for people who are shielding and how to access vital supplies such as food and medicine.
People who cannot leave home and need help should call the National Assistance Helpline on 0800 111 4000, open Monday to Friday, 9am to 5pm.