It's pretty annoying when you are reading a book or article on iPad and suddenly it turns itself from Vertical to Horizontal, or you can say flip itself from Portrait to Landscape. Doesn't matter, whether you like a Horizontal iPad or Vertical iPad screen orientation for reading, but you surely don't want to switch between them with slight movement in hand. I was frustrated and furious about this problem until I found the solution to lock the screen orientation mode on the iPad. Since I am a first-time iPad user, I found it really tricky, where important functionality is hidden with two taps, three taps, etc.