While being a moderator on http://www.allnumis.com a lot of people asked me what are the different orientations of the coins so I thought .. why not explain it here too?
Basically there are 2 types :
1) Coin orientation : It is when you turn the coin on the X (horizontal) axis to the other side and the coin design is upside down.
2) Medal orientation : In this case, if you turn the coin on the horizontal axis to the other side the design is in the good position.
PS : On older coins you will see that they may be neither of medal, neither of coin orientation but to a certain degree (mostly random)