If a law is imposed the entire society, what does this mean

It means that anyone who lives where that law must be followed, is now under that law, also meaning that they have to abide by that law or consequences should be followed for their reckless/bad and ignorant behavior.

operation overlord was the codename for the battle of normandy, the allied operation that launched the successful invasion of german-occupied western europe during world war ii. the operation was launched on 6 june 1944 with the normandy landings