Question from the Algorithmics - Fundamentals test

What does the While loop do?

         sort_insertion(listNumbers) 
         {
                 For i from 1 to size_of_listNumbers - 1 
                 {
                         x <-- listNumbers[i];
                          j <-- i;
                          While j > 0 and listNumbers[j - 1] > x 
                            {
                              listNumbers[j] <-- listNumbers[j - 1]
                              j <-- j-1;
                               
                           }
                            listNumbers[j] <-- x;
                }
    }