title: What is the default behaviour of "Resolve using theirs" in git
body: <p>As per <a href="https://stackoverflow.com/questions/10697463/resolve-git-merge-conflicts-in-favor-of-their-changes-during-a-pull#">this question</a>, I know it is possible to keep all changes that did not raise any conflict, while using <code>their</code>changes for the conflicting changes.</p>
  
  <p>What I would like to know is, when using SourceTree (or, if relevant, any git tool or even the command line), what is the default behaviour when choosing <code>Resolve using theirs</code>on a single file (or even the complete merge).</p>
  
  <ul>
  <li>Does it simply replace the complete local file with whatever is in the remote ?</li>
  <li>Does it keep all the local non conflicting changes and only use <code>theirs</code> for all the conflicts?</li>
  </ul>