title: Difference between size_t and unsigned int?
body: <p>I am so confused about <code>size_t</code>. I have searched on the internet and everywhere mentioned that <code>size_t</code> is an unsigned type so, it can represent only non-negative values.</p>
  
  <p>My first question is: if it is used to represent only non-negative values, why don't we use <code>unsigned int</code> instead of <code>size_t</code>?</p>
  
  <p>My second question is: are <code>size_t</code> and <code>unsigned int</code> interchangeable or not? If not, then why?</p>
  
  <p>And can anyone give me a good example of <code>size_t</code> and briefly its workings?</p>