title: What is the difference between char and unsigned char?
body: <p><strong>(Edited change C/C++ to C)</strong></p>
  
  <p>Please help me to find out a clean clarification on <code>char</code> and <code>unsigned char</code> in C. Specially when we transfer data between embedded devices and general PCs (The difference between buffer of <code>unsigned char</code> and plain <code>char</code>).</p>