Every Block Chain should be mined. Mining is currently associated with Bitcoin and widely known as a way of earning Bitcoins in exchange of the processing power of your computer. This might cause some confusion.
Essentially Mining is a part of a life cycle of any block chain - so to say any Distributed Database which uses Block Chain Technology. Mining is the way to verify changes which happened in the database - block chain transactions in a way that it can't be faked.
Junk (stub)
Ether(started)