change text of a label

Question

hello everyone, my question on this statement I do not understand that meant?

here is my statement that I find on video of Tutorial - How to Download a File from Internet.

 

lblStatus.text=$"Downloaded {String.Format("{0:0.##}",percentage)}%"; 

In this statement I do not understand the usefulness of using $?

in addition it opens the quote in "Downloaded and closed it in }%"?

is that possible to do like this? !!!