user220: I've been hearing a lot about clones and counterfeits. What are the differences between the two?

user27: A clone is an exact or almost exact replica of an original Arduino board, with a different branding.
A derivative is a board based or inspired by Arduino boards, with some specific addition or modification (different layouts, built-in sensors...)
A counterfeit is a clone of an Arduino board, with the same branding of an Arduino board.
More info on an article on the Arduino blog.

user220: The difference is simple: 
Clones don't say "Arduino," where counterfeits do
If I were to create 200 boards all labeled "Arduino UNO R3," it would be a counterfeit. If I were to call them "Happyduino," it would be a clone. 

Note: You can still write Happyduino (Arduino Compatible) on your product. Here's a quote from the Arduino FAQ section

Not okay:

Arduino Xxxxxx
Xxxxxx Arduino
Arduino Compatible Xxxxxx - use "Xxxxxx (Arduino-Compatible)" instead

Okay:

Xxxxxx for Arduino - products that work with official Arduino boards    (e.g. shields or kits)
Xxxxxx (Arduino-Compatible) - variations and clones which are    software and hardware compatible

Note that while we don't attempt to restrict uses of the "duino"
  suffix, its use causes the Italians on the team to cringe (apparently
  it sounds terrible); you might want to avoid it. (It's also
  trademarked by a Hungarian company.)


220: <p>I've been hearing a lot about clones and counterfeits. <strong>What are the differences between the two?</strong></p>
 27: <p>A <strong>clone</strong> is an exact or almost exact replica of an original Arduino board, with a different branding.</p>

<p>A <strong>derivative</strong> is a board based or inspired by Arduino boards, with some specific addition or modification (different layouts, built-in sensors...)</p>

<p>A <strong>counterfeit</strong> is a clone of an Arduino board, with the same branding of an Arduino board.</p>

<p>More info on an <a href="http://blog.arduino.cc/2013/07/10/send-in-the-clones" rel="noreferrer">article</a> on the Arduino blog.</p>
 220: <p>The difference is simple: </p>

<h2>Clones don't say "Arduino," where counterfeits do</h2>

<p>If I were to create 200 boards all labeled "Arduino UNO R3," it would be a counterfeit. If I were to call them "Happyduino," it would be a <em>clone</em>. </p>

<hr>

<p><strong>Note:</strong> You can still write <em>Happyduino (Arduino Compatible)</em> on your product. Here's a quote from the <a href="http://arduino.cc/en/Main/FAQ">Arduino FAQ section</a></p>

<blockquote>
  <p>Not okay:</p>
  
  <ul>
  <li>Arduino Xxxxxx</li>
  <li>Xxxxxx Arduino</li>
  <li>Arduino Compatible Xxxxxx - use "Xxxxxx (Arduino-Compatible)" instead</li>
  </ul>
  
  <p>Okay:</p>
  
  <ul>
  <li>Xxxxxx for Arduino - products that work with official Arduino boards    (e.g. shields or kits)</li>
  <li>Xxxxxx (Arduino-Compatible) - variations and clones which are    software and hardware compatible</li>
  </ul>
  
  <p>Note that while we don't attempt to restrict uses of the "duino"
  suffix, its use causes the Italians on the team to cringe (apparently
  it sounds terrible); you might want to avoid it. (It's also
  trademarked by a Hungarian company.)</p>
</blockquote>
