When you download and install a BTC client,  a new "wallet.dat" is created.
This file contains your address(that you use to receive and sent payment) and privet keys that are contacted to each of the address.
*every time you create a new a address a new privet key is created.
**you can create address for sending and for receiving bitcoins     

Every time you send and receive payments via different address a new block is being created( A block is a record of some or all of the most recent Bitcoin transactions and not just your one transaction)

this block contains the address number, the privet  key that is connected to it and the amount of bitcoins that were transferred. 

As soon as this block is created it is automatically added to the block chain, which is the entire bitcoin history transaction data base.

because the BTC network is a p2p network your client going to download the entire block-chain history from other BTC users when you first install it and it is going to update every time a new block is created.

Your bitcoin client doesn't contain any coin at all, all it does is compering the privet keys in your "wallet.dat" file to the block-chain data base. as soon as it finds all the blocks with your privet keys it can "build" your bitcoin "balance".

If your "wallet.dat" is destroied the privet keys are lost andso are the founds that are connected to that keys.

Am I getting the idea right?


few questions,
1.can you open the same "Wallet.dat" on more then one computer(logic says yes)?

From what I understand every new block contains an answer to a mathematical puzzle and the solving of this puzzle takes time, after the solution is found the network verifies it and ads the block to the block-chain.

1.Why is this process(mining) made to be so difficult and time consuming?
2.if people stop mining there wont be any records(blocks) of new transactions..how does BTC solves this?
3.from what I understand a regular  BTC client or BTC wallet doesn't do mining at all?
4.Who verifies that the answer is correct?