title: Where can I find the diff algorithm?
body: <p>Where can I find an explanation and implementation of the diff algorithm?</p>
  
  <p>First of all I have to recognize that I'm not sure if this is the correct name of the algorithm. For example, how does Stack Overflow mark the differences between two edits of the same question?</p>
  
  <p>PS: I know the C and PHP programming languages.</p>