What does '\\' represent in R?

Hi guys,

For this gsub function below I understand how it works, it is just replacing the $ with nothing. But I haven’t found a clear explanation of what this double escape character (**\ **) means in R and what is it doing here. why is it here and why is there 2 of them. Can someone help please.

Thanks
Martin

fruit %>%
mutate(price=gsub(‘\$’,‘’,price)) ← Note: when publish this post it deletes one of the \ for some reason on this webpage. It should be 2 back slashes

https://www.codecademy.com/paths/analyze-data-with-r/tracks/working-with-data-in-r-skill-path/modules/learn-r-data-cleaning/lessons/r-data-cleaning/exercises/string-parsing