The Welsh government is imposing a 16-day lockdown across the country to regain control of the pandemic.
The First Minister, Labour's Mark Drakeford, said that without a lockdown the NHS in Wales would not be able to cope in the weeks and months ahead.
However there’s been dismay and anger in parts of Wales where the number of coronavirus cases is still relatively low.
People will have to stay at home unless they're key workers or can't work from home. Pubs, restaurants, hotels and all non-essential shops will close.
Primary schools will reopen after half-term. Secondary school Years 7 and 8 will return but other pupils will learn from home.
Gatherings indoors and outdoors with people from other households will not be allowed.
Huw Edwards presents BBC News at Ten reporting by Wales correspondent Hywel Griffith.
