title: Difference between .h files and .inc files in c
body: <p>I have been looking at various open source projects, and they have a bunch of files written in C that have <code>.inc</code> as a file extension. As far as I can tell, they are used like header files.</p>
  
  <p>I thought the standard convention was to use <code>.h</code> files for header files and <code>.c</code> for source files. So, is there a standard convention on when a header file should be an <code>.inc</code> file rather than being a <code>.h</code> file, or are these decided only at a per project basis? (Or am I just looking at weird projects that use <code>.inc</code>?)</p>