BOSTON (CBS) – Social distancing is a key step in fighting the coronavirus and the reason why many colleges are sending kids home.

But what is social distancing? And how is it different from self-quarantine?

WBZ-TV's Dr. Mallika Marshall said, "You should self-quarantine if you have been exposed to someone with coronavirus but are not symptomatic. That means staying home and not going out in public for 14 days."

But social distancing, she said, is something everyone should do, especially those in high-risk groups like the elderly or people with underlying health conditions. You can go out, but be mindful.

To help people keep their distance, Dr. Marshall recommends.

• Avoid mass gatherings
• Try to stay about 6 feet away from people
• Avoid self-service or buffets at restaurants

However, she said, people in high0rish groups should try to stay home as much as possible.