title: how can the computer distinguishes between keyboard USB and mouse USB?
body: <p>Wondering how can the <em>PC</em> distinguish among multiple <strong>USBs</strong>. For example, when i plug my flash drive USB into my computer how can it know that it is a flash drive <strong>USB</strong> not a keyboard <strong>USB</strong> ?</p>
  
  <p><em>Thanks in advance.</em></p>