Yang is the currency of Metin2, in other games known as gold or coins. The more Yang you have, you can get more or better items. Yang is usually dropped by Monsters, and you can receives recieve it also from fulfilling Quests. However you can also make yang by selling items - either to NPC or on the market.
A Yangbomb (or also called jackpot) means an above average Yang-drop from a monster.
Abbreviations for Yang
1.000 Yang = 1k
10.000 Yang = 10k
100.000 Yang = 100k
1.000.000 Yang = 1M (or 1kk)
10.000.000 Yang= 10M (or 10kk)
100.000.000 Yang= 100M (or 100kk)
1.000.000.000 Yang= 1B
k = Thousand (kk = Million)
M = Million
B = Billion
Transferring Yang to your other characters
In order to give Yang to the 2nd, 3rd and/or 4th Char on your account, you can buy silver or gold bars in the value of 50.000, 100,000, 500,000, 1.000.000 or 2.000.000 Yang at the storekeeper. Though, this will cost somewhat more than it's worth. Move the bars into your storage and get them with the desired character again. Then you can sell the bars for the value (-3% tax rate) to a NPC.
If you have a lot patience, you can also make pictures with Yang.