title: Cmake Internals - target_link_libraries
body: <p>Suppose I have a directory dir that contains the followings files: libpippo.so and libpippo.a</p>
  
  <pre><code>#CMAKE CODE
  ...
  link_directories(${dir})
  ...
  target_link_libraries(program pippo). 
  </code></pre>
  
  <p>What happens practically with the command target_link_libraries ? </p>
  
  <p>If am I right, Cmake prefer to use dynamically library if not specified, that's true?</p>
  
  <p>If so, in which way it control that everything is fine? It just check that the library and the required symbolic link are present? It also save the link "dir/libpippo.so" in order to know how where to found the library when the programm will be launched?</p>