More than half the people in the UK will be under some form of local lockdown this week due to coronavirus restrictions.
In England, half the population will be living either in Tier 2 areas, meaning a "high" alert level, or Tier 3 areas, meaning "very high" as new measures are brought in.
From Saturday, London, Essex, Elmbridge, Barrow-in-Furness, York, North East Derbyshire, Erewash and Chesterfield will move into the second tier, joining other areas including Greater Manchester.
Tier 2 means no-one can meet people from different households indoors in public or private, unless they are part of a support bubble. They can still meet people outdoors but only in groups of up to six.
Liverpool City Region has Tier 3 restrictions, which include the closure of pubs and bars unless they can operate as restaurants.
Tier 1 in the lowest level, which includes the rule of six and curfews for pubs and restaurants.
Here, we look more at the rules that all of us will have to follow, how they differ in England, Scotland, Wales and Northern Ireland, and the specific restrictions being enforced in certain areas.
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