The R number

The UK Statistics Authority recently published guidance on how to discuss R, the reproduction number. During the COVID-19 outbreak there has been a lot of media coverage focusing on this number and this guidance is likely a response to some of the misinterpretations of this number -
https://www.statisticsauthority.gov.uk/publication/presenting-estimates-of-r-by-government-and-allied-bodies-across-the-united-kingdom/

A simple description of R, the average number of secondary infections produced by 1 infected person, is helpful to broadly understand the concept but like most epidemiological concepts there are many additional factors to consider. This is further explained in this article from the BMJ - https://www.bmj.com/content/bmj/369/bmj.m1891.full.pdf

In the UK, the R number has been a key component in the government’s strategy to lift lockdown measures. More information on how the UK uses the R number can be found here - https://www.gov.uk/guidance/the-r-number-in-the-uk

Before the pandemic had you heard of the R number? Has it helped you to understand why certain restrictions were put in place to reduce the spread of COVID-19? Are there other epidemiological terms being used in your country to keep you up to date with your country's progress?