+ represents the amount of increased code, and the same - represents the amount of code deleted.
4 +- indicates that four lines have changed, and the others are similar. You can see

  
 + code adds code,-represents deletion, while PP+-, 's personal understanding means that many changes have taken place, including adding and deleting code, because you said that git pull came down, he may not only represent this modification to the file, but may also include changes to the file in your previous submission, or branch, and then another developer has also modified the file, recording the total number of 
.