title: GIT: How to Jump to Different Branches without Deleting Files
body: <p>This is my flow of work:</p>
  
  <p>Under 'master': git checkout -b branch_x</p>
  
  <p>Under 'branch_x': create and save file 'abc'</p>
  
  <p>Under 'branch_x': git checkout master</p>
  
  <p>Under 'master': git checkout -b branch_y</p>
  
  <p>Under 'branch_y': create and save file 'def'</p>
  
  <p>Now when I try to do pull origin, I got rejected because it says there is a file 'abc' there. If I delete 'abc', the pull origin branch_y goes through, but if I go back to branch_x, 'abc' is gone from there too.</p>
  
  <p>Questions are: 1. Why Branch Y sees 'abc' too? It's created in Branch X! 2. How can I upload whatever I did on Branch Y without touching anything under Branch X?</p>
  
  <p>Thanks!</p>