title: How do I use CMake?
body: <p>I am trying to use CMake in order to compile opencv.</p>
  
  <p>I am reading the <a href="http://www.cmake.org/cmake/help/cmake_tutorial.html#s3">tutorial</a> but can't understand what is CMakeLists files and how is it connected to the gui of CMake?</p>
  
  <p>Also couldn't understand what are makefiles, are they the same is CMakeLists?  </p>
  
  <p>And which file is it which I in the end open with visual-studio?</p>