How are prints labled?

The point of prints is to make multiples ... How do artists number them?
What is an 'artist's proof'?


**An artist makes an edition - a total number of prints and numbers each one in the series as a 'fraction' a number over the total. For instance the second print in an edition of 24 is marked 
2/24.
### a proof is a print not in an edition usually taken before the edition is printed.