Today I got my clone Arduino and connected it to my real Arduino and they both work. (UPDATE: The Arduino noted as real Arduino probably also is not a real Arduino; however both work fine).
However, I see some differences and wonder if these are good or bad:
1) At number 1 there is on the clone arduino a 12 MHz oscillator? What does it do? And since there is also the regular 16 MHz oscillator I wonder why there are two.
2) At number 2 are 4 holes without any explanation. What is the function?
3) At 3 there are 12 holes (sorry that only 9 are visible, under the blue/black cable are 4 more holes with silver square around them.
4) At 4 there is a SCL and SDA which are used for SPI I think, but these are not on the original Arduino. But the original Arduino has 6 pins at the same location and 4 holes (where 2 of them are marked as JP2).