Quote from: Badabing on July 06, 2013, 12:10:24 PM

Someone send me 30 bitcoins and it show on the blockchain even it does not have any confirmation yet.

No, it doesn't.

The definition of a "confirmation" is to be in a block on "the blockchain". If it is in a block on "the blockchain", then you have a confirmation (although your wallet might not be showing that confirmation if it isn't properly synchronized).

Note, that blockchain.info is not "the blockchain". blockchain.info is just a website someone created that has a lot of useful bitcoin related information. They decided to call their website blockchain.info. It is a very useful website, and many people like and rely on it, but there is nothing "official" about it. If you see a transaction at blockchain.info, it is not necessarily on "the blockchain", since blockchain.info also lists all the transactions that are in the memory pool (and therefore not yet on the blockchain.