Can someone will me to clarify me.... Actually what is nonce and what is relation between a nice and transaction number
If you ready my post above, the answer should be there. You can read all about what a nonce is here:
https://en.bitcoin.it/wiki/Nonce Also, as this thread is about and answered already, the only relation between a nonce and a transaction is a transaction is included in a block, and a block has a nonce. There is no direct relation between nonce and transaction.
When a block is made, the
Block Header is hashed, this hash has to be lower then the current
Target. The target is a 256 bit number engineered to allow for a valid Block Hash to occur roughly every 10 minutes. The lower the Target gets, the harder it is to produce a valid hash. When you hash the block header, it produces a value based on the data being hashed. This value is the same if the data inside is the same, but if any part of the data changes, the hash is entirely different. When miners are hashing the headers, if the hash is not lower than the target, they increase the nonce (which is included in the block header, and its purpose is exactly this, to change the resulting hash) then hash again producing a different hash (with the same set of transaction details, etc), and repeat this until the hash beats the target.
